QoS flow control method and apparatus

ABSTRACT

This application provides a QoS flow control method and an apparatus. An SMF network element receives first indication information sent by an access network apparatus, where the first indication information is used to indicate that a first QoS target of a QoS flow cannot be met; and the SMF network element does not process the QoS flow if the SMF network element receives second indication information in a first preset time; or the SMF network element deletes or modifies the QoS flow if the SMF network element does not receive second indication information in a first preset time, where the second indication information is used to indicate that the first QoS target can be met.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/CN2019/071834, filed on Jan. 15, 2019, which claims priority toChinese Patent Application No. 201810041613.8, filed on Jan. 16, 2018.The disclosures of the aforementioned applications are herebyincorporated by reference in their entireties.

TECHNICAL FIELD

This application relates to communications technologies, and inparticular, to a quality of service (QoS) flow control method and anapparatus.

BACKGROUND

In a 5th generation (5G) mobile communications system, a 5G QoS modelbased on a QoS flow is proposed, to ensure end-to-end quality of serviceof a service. The 5G QoS model includes a guaranteed bit rate QoS flow(GBR QoS flow) and a non-guaranteed bit rate QoS flow (Non-GBR QoSflow). Same transmission processing (such as scheduling or an admissionthreshold) is performed on data packets included in a same QoS flow.

User equipment (UE) may establish one or more packet data unit (PDU)sessions with a 5G system. One or more QoS flows may be established ineach PDU session. Each QoS flow is identified by one QoS flow identifier(QFI), and the QFI uniquely identifies a QoS flow in a session. GBR QoSflows include a GBR QoS flow that uses notification control and a GBRQoS flow that does not use notification control. Notification control isused to indicate whether notifications are requested from an accessnetwork (AN)/a radio access network (RAN) when a guaranteed flow bitrate (GFBR) can no longer be guaranteed for a QoS flow during thelifetime of the QoS flow. In an existing GBR QoS flow that usesnotification control, after the GBR QoS flow is established, whendetecting, at any moment, that a QoS target of a corresponding GBR QoSflow cannot be met, the (R)AN sends indication information to a sessionmanagement function (SMF) network element. Further, the SMF networkelement determines to initiate a QoS flow modification or deletionprocedure.

However, a resource shortage of the (R)AN may be temporary. Therefore,some services cannot be served or a service with reduced quality isprovided if the SMF network element immediately deletes the QoS flow ormodifies the QoS flow to lower the QoS target when receiving theindication information indicating that the QoS target cannot be met.

SUMMARY

This application provides a QoS flow control method and an apparatus, toresolve a problem that a QoS flow cannot be served or quality of serviceof a service is reduced because an SMF network element immediatelydeletes or modifies the QoS flow when resources of an access networkapparatus are temporarily short.

A first aspect of this application provides a QoS flow control method,including: receiving, by a session management function SMF networkelement, first indication information sent by an access networkapparatus, where the first indication information is used to indicatethat a first QoS target of a QoS flow cannot be met, the first QoStarget includes a first guaranteed flow bit rate GFBR, and the QoS flowis a flow on which same QoS processing is performed; and skipping, bythe SMF network element, processing the QoS flow if the SMF networkelement receives, in a first preset time, second indication informationsent by the access network apparatus, where the second indicationinformation is used to indicate that the first QoS target can be met; ordeleting or modifying, by the SMF network element, the QoS flow if theSMF network element does not receive, in the first preset time, thesecond indication information sent by the access network apparatus.

In the method, when a QoS target of the QoS flow cannot be met, the SMFnetwork element does not immediately delete or modify the QoS flow.Instead, the SMF network element deletes or modifies the QoS flow onlywhen the QoS target of the QoS flow still cannot be met within a delayof the first preset time, to avoid a problem that a QoS flow servicecannot be served or quality of service of a service is reduced becausethe SMF network element immediately deletes or modifies the QoS flowwhen resources of the access network apparatus are temporarily short.

In a possible implementation, the SMF network element deletes ormodifies the QoS flow if the SMF network element receives, in the firstpreset time, third indication information sent by the access networkapparatus, where the third indication information is used to indicatethat the first QoS target cannot be met.

In a possible implementation, the method further includes: determining,by the SMF network element based on the first indication information, anoperation to be performed on the QoS flow, where the operation is thedeleting or modifying the QoS flow, and a state of the operation is ato-be-performed state. Because determining the operation to be performedon the QoS flow and detecting whether the second indication informationis received may be performed concurrently, this implementation canshorten a time of a QoS flow modification procedure and reduce impact ona service compared with determining, after the first preset time, toperform the modification operation on the QoS flow.

In a possible implementation, the modifying, by the SMF network element,the QoS flow includes: determining, by the SMF network element, a secondQoS target of the QoS flow based on QoS policy information, where thesecond QoS target includes a second GFBR, and the QoS policy informationincludes at least first QoS control information and second QoS controlinformation; and sending, by the SMF network element, the second QoStarget to the access network apparatus.

Because at least two pieces of QoS control information included in theQoS policy information can meet a QoS requirement of the QoS flow, thesecond QoS target determined based on the QoS control information canmeet the QoS requirement of the QoS flow. Different from the prior art,in the solution in this application, a QoS target of the QoS flow ismodified from the first QoS target to the second QoS target, and QoSquality of the QoS flow is not reduced.

In a possible implementation, the QoS policy information furtherincludes at least priority information of the first QoS controlinformation and priority information of the second QoS controlinformation; and the determining, by the SMF network element, a secondQoS target of the QoS flow based on QoS policy information includes:determining, by the SMF network element, the second QoS target of theQoS flow based on the priority information of the first QoS controlinformation and the priority information of the second QoS controlinformation that are included in the QoS policy information.

In a possible implementation, the determining, by the SMF networkelement, a second QoS target of the QoS flow based on QoS policyinformation includes: determining, by the SMF network element, thesecond QoS target of the QoS flow based on guaranteed bit flow GBRinformation of the first QoS control information and GBR information ofthe second QoS control information that are included in the QoS policyinformation.

In a possible implementation, the determining, by the SMF networkelement, a second QoS target of the QoS flow based on QoS policyinformation includes: determining, by the SMF network element, at leastone third QoS target based on the first QoS control information and thesecond QoS control information that are included in the QoS policyinformation; sending, by the SMF network element, the third QoS targetto the access network apparatus; receiving, by the SMF network element,a fourth QoS target sent by the access network apparatus, where thefourth QoS target is determined by the access network apparatus based onthe third QoS target, and the fourth QoS target is a QoS target that canbe met by the access network apparatus; and determining, by the SMFnetwork element, the second QoS target based on the fourth QoS target.

The SMF network element and the access network apparatus determine thesecond QoS target through negotiation, so that it can be ensured thatthe second QoS target determined for the QoS flow matches a resource ofthe access network apparatus, and the resource of the access networkapparatus can be used to a maximum extent.

In a possible implementation, the method further includes: sending, bythe SMF network element, at least two QoS targets of the QoS flow to theaccess network apparatus based on the QoS policy information; andreceiving, by the SMF network element, a fifth QoS target sent by theaccess network apparatus, where the fifth QoS target is a QoS targetthat can be met by the access network apparatus, and the fifth QoStarget is determined by the access network apparatus based on the atleast two QoS targets when the first QoS target of the QoS flow cannotbe met; and the determining, by the SMF network element, a second QoStarget of the QoS flow based on QoS policy information includes:determining, by the SMF network element, the second QoS target based onthe fifth QoS target.

The SMF network element and the access network apparatus determine thesecond QoS target through negotiation, so that it can be ensured thatthe second QoS target determined for the QoS flow matches a resource ofthe access network apparatus, and the resource of the access networkapparatus can be used to a maximum extent.

In a possible implementation, the method further includes: receiving, bythe SMF network element, the QoS policy information sent by a policycontrol function PCF network element, where the QoS policy informationis generated by the PCF network element based on at least two QoSrequirements sent by an application function AF network element.

A second aspect of this application provides a QoS flow control method,including: sending, by an access network apparatus, first indicationinformation to a session management function SMF network element, wherethe first indication information is used to indicate that a first QoStarget of a QoS flow of user equipment UE cannot be met, the first QoStarget comprises a first guaranteed flow bit rate GFBR, and the firstQoS flow is a flow on which same QoS processing is performed; and if thefirst QoS target can be met in a second preset time, sending, by theaccess network apparatus, second indication information to the SMFnetwork element, where the second indication information is used toindicate that the first QoS target can be met.

After sending the first indication information, the access networkapparatus detects, in the second preset time, whether the first QoStarget can be met, and notifies the SMF network element, so that when aQoS target of the QoS flow cannot be met, the SMF network element doesnot immediately delete or modify the QoS flow. Instead, the SMF networkelement deletes or modifies the QoS flow only when the QoS target of theQoS flow still cannot be met within a delay of the first preset time, toavoid a problem that a QoS flow service cannot be served or quality ofservice of a service is reduced because the SMF network elementimmediately deletes or modifies the QoS flow when resources of theaccess network apparatus are temporarily short.

In a possible implementation, the method further includes: if the firstQoS target cannot be met in the second preset time, sending, by theaccess network apparatus, third indication information to the SMFnetwork element, where the third indication information is used toindicate that the first QoS target cannot be met.

In a possible implementation, the method further includes: if the accessnetwork apparatus does not receive a modification procedure or deletionprocedure that is for the QoS flow and that is sent by the SMF networkelement, sending, by the access network apparatus, a deletion requestfor the QoS flow to the SMF network element.

In a possible implementation, the method further includes: calculating,by a timer, the second preset time; and deleting, by the access networkapparatus, the timer if the access network apparatus receives, in thesecond preset time, a deletion or modification request that is for theQoS flow and that is sent by the SMF network element.

In a possible implementation, the method further includes: receiving, bythe access network apparatus, a second QoS target sent by the SMFnetwork element, where the second QoS target includes a second GFBR; andmodifying, by the access network apparatus, the QoS flow based on thesecond QoS target.

In a possible implementation, before the receiving, by the accessnetwork apparatus, a second QoS target sent by the SMF network element,the method further includes: receiving, by the access network apparatus,at least one third QoS target sent by the SMF network element;determining, by the access network apparatus, a fourth QoS target basedon the third QoS target, where the fourth QoS target is a QoS targetthat can be met by the access network apparatus; and sending, by theaccess network apparatus, the fourth QoS target to the SMF networkelement.

In a possible implementation, before the sending, by an access networkapparatus, first indication information to a session management functionSMF network element, the method further includes: receiving, by theaccess network apparatus, at least two QoS targets of the QoS flow thatare sent by the SMF network element; when the first QoS target of theQoS flow cannot be met, selecting, by the access network apparatus, afifth QoS target from the at least two QoS targets, where the fifth QoStarget is a QoS target that can be met by the access network apparatus;and sending, by the access network apparatus, the fifth QoS target tothe SMF network element, so that the SMF network element determines thesecond QoS target based on the fifth QoS target.

A third aspect of this application provides a quality of service QoSflow control method, including: receiving, by a policy control functionPCF network element, first indication information sent by a sessionmanagement function SMF network element, where the first indicationinformation is used to indicate that a first QoS target of a servicecannot be met, and the first QoS target includes a first guaranteed bitrate GBR; and skipping, by the PCF network element, processing a QoSpolicy rule of the service if the PCF network element receives, in afirst preset time, second indication information sent by the SMF networkelement, where the second indication information is used to indicatethat the first QoS target can be met; or deleting or modifying, by thePCF network element, a QoS policy rule of the service if the PCF networkelement does not receive, in the first preset time, the secondindication information sent by the SMF network element.

In the method, when a QoS target of a QoS flow cannot be met, the PCFnetwork element does not immediately delete or modify the QoS policyrule that is of the service and that corresponds to the QoS flow.Instead, the PCF network element deletes or modifies the QoS policy ruleof the service only when the QoS target of the QoS flow still cannot bemet within a delay of the first preset time, to avoid a problem that aQoS flow service cannot be served or quality of service of a service isreduced because the PCF network element immediately deletes or modifiesthe QoS flow when resources of the access network apparatus aretemporarily short.

In a possible implementation, the PCF network element deletes ormodifies the QoS policy rule of the service if the PCF network elementreceives, in the first preset time, third indication information sent bythe SMF network element, where the third indication information is usedto indicate that the first QoS target cannot be met.

In a possible implementation, the method further includes: determining,by the PCF network element based on the first indication information, anoperation to be performed on the service, where the operation is thedeleting or modifying a QoS policy rule of the service, and a state ofthe operation is a to-be-performed state. Because determining theoperation to be performed on the QoS policy rule and detecting whetherthe second indication information is received may be performedconcurrently, this implementation can shorten a time for modifying theQoS policy rule and reduce impact on the service compared withdetermining, after the first preset time, to perform the modificationoperation on the QoS policy rule.

In a possible implementation, the modifying, by the PCF network element,a QoS policy rule of the service includes: determining, by the PCFnetwork element, a second QoS target of the service based on QoS policyinformation, where the second QoS target includes a second GBR, and theQoS policy information includes at least first QoS control informationand second QoS control information; and sending, by the PCF networkelement, the second QoS target to the SMF network element.

Because at least two pieces of QoS control information included in theQoS policy information can meet a QoS requirement of the service, thesecond QoS target that is of the service and that is determined by thePCF network element based on the QoS control information can meet theQoS requirement of the service. Different from the prior art, in thesolution in this application, a QoS target of the service is modifiedfrom the first QoS target to the second QoS target, and QoS quality ofthe service is not reduced.

In a possible implementation, the QoS policy information furtherincludes priority information of the first QoS control information andpriority information of the second QoS control information; and thedetermining, by the PCF network element, a second QoS target of theservice based on QoS policy information includes: determining, by thePCF network element, the second QoS target of the service based on thepriority information of the first QoS control information and thepriority information of the second QoS control information that areincluded in the QoS policy information.

In a possible implementation, the determining, by the PCF networkelement, a second QoS target of the service based on QoS policyinformation includes: determining, by the PCF network element, thesecond QoS target of the service based on guaranteed bit flow GBRinformation of the first QoS control information and GBR information ofthe second QoS control information that are included in the QoS policyinformation.

In a possible implementation, the determining, by the PCF networkelement, a second QoS target of the QoS flow based on QoS policyinformation includes: determining, by the PCF network element, at leastone third QoS target based on the first QoS control information and thesecond QoS control information that are included in the QoS policyinformation; sending, by the PCF network element, the third QoS targetto the SMF network element; receiving, by the PCF network element, afourth QoS target sent by the SMF network element, where the fourth QoStarget is determined by the SMF network element based on a QoS targetthat can be met by an access network apparatus; and determining, by thePCF network element, the second QoS target based on the fourth QoStarget.

The PCF network element and the access network apparatus determine thesecond QoS target of the service through negotiation, so that it can beensured that the second QoS target determined for the service matches aresource of the access network apparatus, and the resource of the accessnetwork apparatus can be used to a maximum extent.

In a possible implementation, the method further includes: receiving, bythe PCF network element, a fifth QoS target sent by the SMF networkelement, where the fifth QoS target is determined by the SMF networkelement based on a QoS target that can be met by an access networkapparatus; and the determining, by the PCF network element, a second QoStarget of the service based on QoS policy information includes:determining, by the PCF network element, the second QoS target based onthe fifth QoS target.

The PCF network element and the access network apparatus determine thesecond QoS target of the service through negotiation, so that it can beensured that the second QoS target determined for the service matches aresource of the access network apparatus, and the resource of the accessnetwork apparatus can be used to a maximum extent.

In a possible implementation, the method further includes: receiving, bythe PCF network element, at least two QoS requirements sent by anapplication function AF network element; and generating, by the PCFnetwork element, the QoS policy information based on the at least twoQoS requirements.

A fourth aspect of this application provides a QoS flow control method,including: receiving, by an application function AF network element,first indication information sent by a policy control function PCFnetwork element, where the first indication information is used toindicate that a first QoS target of a service cannot be met, and thefirst QoS target includes a first guaranteed bit rate GBR; and skipping,by the AF network element, processing a QoS requirement of the serviceif the AF network element receives, in a first preset time, secondindication information sent by the PCF network element, where the secondindication information is used to indicate that the first QoS target canbe met; or deleting or modifying, by the AF network element, a QoSrequirement of the service if the AF network element does not receive,in the first preset time, the second indication information sent by thePCF network element.

In the method, when a QoS target of a QoS flow cannot be met, the AFnetwork element does not immediately delete or modify the QoSrequirement that is of the service and that corresponds to the QoS flow.Instead, the AF network element deletes or modifies the QoS requirementof the service only when the QoS target of the QoS flow still cannot bemet within a delay of the first preset time, to avoid a problem that aQoS flow service cannot be served or quality of service of a service isreduced because the AF network element immediately deletes or modifiesthe QoS flow when resources of the access network apparatus aretemporarily short.

In a possible implementation, the AF network element deletes or modifiesthe QoS requirement of the service if the AF network element receives,in the first preset time, third indication information sent by the PCFnetwork element, where the third indication information is used toindicate that the first QoS target cannot be met.

In a possible implementation, the method further includes: determining,by the AF network element based on the first indication information, anoperation to be performed on the service, where the operation is thedeleting or modifying a QoS requirement of the service, and a state ofthe operation is a to-be-performed state. Because determining themodification operation to be performed on the QoS requirement anddetecting whether the second indication information is received may beperformed concurrently, this implementation can shorten a time formodifying the QoS requirement and reduce impact on the service comparedwith determining, after the first preset time, to perform themodification operation on the QoS requirement.

In a possible implementation, the modifying, by the AF network element,a QoS requirement of the service includes: determining, by the AFnetwork element, a second QoS target of the service based on QoS policyinformation, where the second QoS target includes a second GBR, and theQoS policy information includes at least first QoS requirementinformation and second QoS requirement information; and sending, by theAF network element, the second QoS target to the PCF network element.

Because the at least two pieces of QoS requirement information includedin the QoS policy information can meet the QoS requirement of theservice, the second QoS target that is of the service and that isdetermined by the AF network element based on QoS control informationcan meet the QoS requirement of the service. Different from the priorart, in the solution in this embodiment, a QoS target of the service ismodified from the first QoS target to the second QoS target, and QoSquality of the service is not reduced.

In a possible implementation, the QoS policy information furtherincludes priority information of the first QoS requirement informationand priority information of the second QoS requirement information; andthe determining, by the AF network element, a second QoS target of theservice based on QoS policy information includes: determining, by the AFnetwork element, the second QoS target of the service based on thepriority information of the first QoS requirement information and thepriority information of the second QoS requirement information that areincluded in the QoS policy information.

In a possible implementation, the determining, by the AF networkelement, a second QoS target of the service based on QoS policyinformation includes: determining, by the AF network element, the secondQoS target of the service based on guaranteed bit rate GBR informationof the first QoS requirement information and GBR information of thesecond QoS requirement information that are included in the QoS policyinformation.

In a possible implementation, the determining, by the AF networkelement, a second QoS target of the QoS flow based on QoS policyinformation includes: determining, by the AF network element, at leastone third QoS target based on the first QoS requirement information andthe second QoS requirement information that are included in the QoSpolicy information; sending, by the AF network element, the third QoStarget to the PCF network element; receiving, by the AF network element,a fourth QoS target sent by the PCF network element, where the fourthQoS target is determined by the PCF network element based on a QoStarget that can be met by an access network apparatus; and determining,by the AF network element, the second QoS target based on the fourth QoStarget.

The AF network element and the access network apparatus determine thesecond QoS target of the service through negotiation, so that it can beensured that the second QoS target determined for the service matches aresource of the access network apparatus, and the resource of the accessnetwork apparatus can be used to a maximum extent.

In a possible implementation, the method further includes: receiving, bythe AF network element, a fifth QoS target sent by the PCF networkelement, where the fifth QoS target is determined by the PCF networkelement based on a QoS target that can be met by an access networkapparatus; and the determining, by the AF network element, a second QoStarget of the service based on QoS policy information includes:determining, by the AF network element, the second QoS target based onthe fifth QoS target.

The AF network element and the access network apparatus determine thesecond QoS target of the service through negotiation, so that it can beensured that the second QoS target determined for the service matches aresource of the access network apparatus, and the resource of the accessnetwork apparatus can be used to a maximum extent.

A fifth aspect of this application provides a QoS flow control method,including: receiving, by an SMF network element, first indicationinformation sent by an access network apparatus, where the firstindication information is used to indicate that a first QoS target of aQoS flow cannot be met, the first QoS target includes a first GFBR, andthe QoS flow is a flow on which same QoS processing is performed;determining, by the SMF network element, a second QoS target of the QoSflow based on QoS policy information, where the second QoS targetincludes a second GFBR, and the QoS policy information includes at leastfirst QoS control information and second QoS control information; andsending, by the SMF network element, the second QoS target to the accessnetwork apparatus.

In a possible implementation, the QoS policy information furtherincludes at least priority information of the first QoS controlinformation and priority information of the second QoS controlinformation; and the determining, by the SMF network element, a secondQoS target of the QoS flow based on QoS policy information includes:determining, by the SMF network element, the second QoS target of theQoS flow based on the priority information of the first QoS controlinformation and the priority information of the second QoS controlinformation that are included in the QoS policy information.

In a possible implementation, the determining, by the SMF networkelement, a second QoS target of the QoS flow based on QoS policyinformation includes: determining, by the SMF network element, thesecond QoS target of the QoS flow based on guaranteed bit flow GBRinformation of the first QoS control information and GBR information ofthe second QoS control information that are included in the QoS policyinformation.

In a possible implementation, the determining, by the SMF networkelement, a second QoS target of the QoS flow based on QoS policyinformation includes: determining, by the SMF network element, at leastone third QoS target based on the first QoS control information and thesecond QoS control information that are included in the QoS policyinformation; sending, by the SMF network element, the third QoS targetto the access network apparatus; receiving, by the SMF network element,a fourth QoS target sent by the access network apparatus, where thefourth QoS target is determined by the access network apparatus based onthe third QoS target, and the fourth QoS target is a QoS target that canbe met by the access network apparatus; and determining, by the SMFnetwork element, the second QoS target based on the fourth QoS target.

In a possible implementation, the method further includes: sending, bythe SMF network element, at least two QoS targets of the QoS flow to theaccess network apparatus based on the QoS policy information; andreceiving, by the SMF network element, a fifth QoS target sent by theaccess network apparatus, where the fifth QoS target is a QoS targetthat can be met by the access network apparatus, and the fifth QoStarget is determined by the access network apparatus based on the atleast two QoS targets when the first QoS target of the QoS flow cannotbe met; and the determining, by the SMF network element, a second QoStarget of the QoS flow based on QoS policy information includes:determining, by the SMF network element, the second QoS target based onthe fifth QoS target.

In a possible implementation, the method further includes: receiving, bythe SMF network element, the QoS policy information sent by a policycontrol function PCF network element, where the QoS policy informationis generated by the PCF network element based on at least two QoSrequirements sent by an application function AF network element.

A sixth aspect of this application provides a QoS flow control method,including: receiving, by a policy control function PCF network element,first indication information sent by a session management function SMFnetwork element, where the first indication information is used toindicate that a first QoS target of a service cannot be met, and thefirst QoS target includes a first guaranteed bit rate GBR; determining,by the PCF network element, a second QoS target of the service based onQoS policy information, where the second QoS target includes a secondGBR, and the QoS policy information includes at least first QoS controlinformation and second QoS control information; and sending, by the PCFnetwork element, the second QoS target to the SMF network element.

In a possible implementation, the QoS policy information furtherincludes priority information of the first QoS control information andpriority information of the second QoS control information; and thedetermining, by the PCF network element, a second QoS target of theservice based on QoS policy information includes: determining, by thePCF network element, the second QoS target of the service based on thepriority information of the first QoS control information and thepriority information of the second QoS control information that areincluded in the QoS policy information.

In a possible implementation, the determining, by the PCF networkelement, a second QoS target of the service based on QoS policyinformation includes: determining, by the PCF network element, thesecond QoS target of the service based on guaranteed bit flow GBRinformation of the first QoS control information and GBR information ofthe second QoS control information that are included in the QoS policyinformation.

In a possible implementation, the determining, by the PCF networkelement, a second QoS target of the QoS flow based on QoS policyinformation includes: determining, by the PCF network element, at leastone third QoS target based on the first QoS control information and thesecond QoS control information that are included in the QoS policyinformation; sending, by the PCF network element, the third QoS targetto the SMF network element; receiving, by the PCF network element, afourth QoS target sent by the SMF network element, where the fourth QoStarget is determined by the SMF network element based on a QoS targetthat can be met by an access network apparatus; and determining, by thePCF network element, the second QoS target based on the fourth QoStarget.

In a possible implementation, the method further includes: receiving, bythe PCF network element, a fifth QoS target sent by the SMF networkelement, where the fifth QoS target is determined by the SMF networkelement based on a QoS target that can be met by an access networkapparatus; and the determining, by the PCF network element, a second QoStarget of the service based on QoS policy information includes:determining, by the PCF network element, the second QoS target based onthe fifth QoS target.

In a possible implementation, the method further includes: receiving, bythe PCF network element, at least two QoS requirements sent by anapplication function AF network element; and generating, by the PCFnetwork element, the QoS policy information based on the at least twoQoS requirements.

A seventh aspect of this application provides a QoS flow control method,including: receiving, by an application function AF network element,first indication information sent by a policy control function PCFnetwork element, where the first indication information is used toindicate that a first QoS target of a service cannot be met, and thefirst QoS target includes a first guaranteed bit rate GBR; determining,by the AF network element, a second QoS target of the service based onQoS policy information, where the second QoS target includes a secondGBR, and the QoS policy information includes at least first QoSrequirement information and second QoS requirement information; andsending, by the AF network element, the second QoS target to the PCFnetwork element.

In a possible implementation, the QoS policy information furtherincludes priority information of the first QoS requirement informationand priority information of the second QoS requirement information; andthe determining, by the AF network element, a second QoS target of theservice based on QoS policy information includes: determining, by the AFnetwork element, the second QoS target of the service based on thepriority information of the first QoS requirement information and thepriority information of the second QoS requirement information that areincluded in the QoS policy information.

In a possible implementation, the determining, by the AF networkelement, a second QoS target of the service based on QoS policyinformation includes: determining, by the AF network element, the secondQoS target of the service based on guaranteed bit rate GBR informationof the first QoS requirement information and GBR information of thesecond QoS requirement information that are included in the QoS policyinformation.

In a possible implementation, the determining, by the AF networkelement, a second QoS target of the QoS flow based on QoS policyinformation includes: determining, by the AF network element, at leastone third QoS target based on the first QoS requirement information andthe second QoS requirement information that are included in the QoSpolicy information; sending, by the AF network element, the third QoStarget to the PCF network element; receiving, by the AF network element,a fourth QoS target sent by the PCF network element, where the fourthQoS target is determined by the PCF network element based on a QoStarget that can be met by an access network apparatus; and determining,by the AF network element, the second QoS target based on the fourth QoStarget.

In a possible implementation, the method further includes: receiving, bythe AF network element, a fifth QoS target sent by the PCF networkelement, where the fifth QoS target is determined by the PCF networkelement based on a QoS target that can be met by an access networkapparatus; and the determining, by the AF network element, a second QoStarget of the service based on QoS policy information includes:determining, by the AF network element, the second QoS target based onthe fifth QoS target.

An eighth aspect of this application provides a session managementfunction SMF network element, including: a receiving module, configuredto receive first indication information sent by an access networkapparatus, where the first indication information is used to indicatethat a first QoS target of a QoS flow cannot be met, the first QoStarget includes a first guaranteed flow bit rate GFBR, and the QoS flowis a flow on which same QoS processing is performed; and a processingmodule, configured to: skip processing the QoS flow if the receivingmodule receives, in a first preset time, second indication informationsent by the access network apparatus, where the second indicationinformation is used to indicate that the first QoS target can be met; ordelete or modify the QoS flow if the receiving module does not receive,in the first preset time, the second indication information sent by theaccess network apparatus.

In a possible implementation, the processing module is furtherconfigured to delete or modify the QoS flow if the receiving modulereceives, in the first preset time, third indication information sent bythe access network apparatus, where the third indication information isused to indicate that the first QoS target cannot be met.

In a possible implementation, the processing module is furtherconfigured to determine, based on the first indication information, anoperation to be performed on the QoS flow, where the operation is thedeleting or modifying the QoS flow, and a state of the operation is ato-be-performed state.

In a possible implementation, the SMF network element further includes asending module.

The processing module is specifically configured to determine a secondQoS target of the QoS flow based on QoS policy information, where thesecond QoS target includes a second GFBR, and the QoS policy informationincludes at least first QoS control information and second QoS controlinformation.

The sending module is configured to send the second QoS target to theaccess network apparatus.

In a possible implementation, the QoS policy information furtherincludes at least priority information of the first QoS controlinformation and priority information of the second QoS controlinformation; and that the processing module determines a second QoStarget of the QoS flow based on QoS policy information includes:determining the second QoS target of the QoS flow based on the priorityinformation of the first QoS control information and the priorityinformation of the second QoS control information that are included inthe QoS policy information.

In a possible implementation, that the processing module determines asecond QoS target of the QoS flow based on QoS policy informationincludes: determining the second QoS target of the QoS flow based onguaranteed bit flow GBR information of the first QoS control informationand GBR information of the second QoS control information that areincluded in the QoS policy information.

In a possible implementation, that the processing module determines asecond QoS target of the QoS flow based on QoS policy informationincludes: determining at least one third QoS target based on the firstQoS control information and the second QoS control information that areincluded in the QoS policy information, where the sending module isfurther configured to send the third QoS target to the access networkapparatus; and the receiving module is further configured to receive afourth QoS target sent by the access network apparatus, where the fourthQoS target is determined by the access network apparatus based on thethird QoS target, and the fourth QoS target is a QoS target that can bemet by the access network apparatus; and determining the second QoStarget based on the fourth QoS target.

In a possible implementation, the sending module is further configuredto send at least two QoS targets of the QoS flow to the access networkapparatus based on the QoS policy information.

The receiving module is further configured to receive a fifth QoS targetsent by the access network apparatus, where the fifth QoS target is aQoS target that can be met by the access network apparatus, and thefifth QoS target is determined by the access network apparatus based onthe at least two QoS targets when the first QoS target of the QoS flowcannot be met.

That the processing module determines a second QoS target of the QoSflow based on QoS policy information includes: determining the secondQoS target based on the fifth QoS target.

In a possible implementation, the receiving module is further configuredto: receive the QoS policy information sent by a policy control functionPCF network element, where the QoS policy information is generated bythe PCF network element based on at least two QoS requirements sent byan application function AF network element.

A ninth aspect of this application provides an access network apparatus,including: a sending module, configured to send first indicationinformation to a session management function SMF network element, wherethe first indication information is used to indicate that a first QoStarget of a QoS flow of user equipment UE cannot be met, the first QoStarget includes a first guaranteed flow bit rate GFBR, and the first QoSflow is a flow on which same QoS processing is performed.

The sending module is further configured to: if the first QoS target canbe met in a second preset time, send second indication information tothe SMF network element, where the second indication information is usedto indicate that the first QoS target can be met.

In a possible implementation, the sending module is further configuredto: if the first QoS target cannot be met in the second preset time,send third indication information to the SMF network element, where thethird indication information is used to indicate that the first QoStarget cannot be met.

In a possible implementation, the sending module is further configuredto: if the access network apparatus does not receive a modificationprocedure or deletion procedure that is for the QoS flow and that issent by the SMF network element, send a deletion request for the QoSflow to the SMF network element.

In a possible implementation, a timer calculates the second preset time.The access network apparatus further includes: a processing module,configured to delete the timer if the access network apparatus receives,in the second preset time, a deletion or modification request that isfor the QoS flow and that is sent by the SMF network element.

In a possible implementation, the access network apparatus furtherincludes: a receiving module, configured to receive a second QoS targetsent by the SMF network element, where the second QoS target includes asecond GFBR; and a processing module, configured to modify the QoS flowbased on the second QoS target.

In a possible implementation, before receiving the second QoS targetsent by the SMF network element, the receiving module is furtherconfigured to receive at least one third QoS target sent by the SMFnetwork element.

The access network apparatus further includes: a processing module,configured to determine a fourth QoS target based on the third QoStarget, where the fourth QoS target is a QoS target that can be met bythe access network apparatus.

The sending module is further configured to send the fourth QoS targetto the SMF network element.

In a possible implementation, the access network apparatus furtherincludes: a receiving module, configured to receive at least two QoStargets of the QoS flow that are sent by the SMF network element; and aprocessing module, configured to: when the first QoS target of the QoSflow cannot be met, select a fifth QoS target from the at least two QoStargets, where the fifth QoS target is a QoS target that can be met bythe access network apparatus.

The sending module is further configured to send the fifth QoS target tothe SMF network element, so that the SMF network element determines thesecond QoS target based on the fifth QoS target.

A tenth aspect of this application provides a policy control functionPCF network element, including: a receiving module, configured toreceive first indication information sent by a session managementfunction SMF network element, where the first indication information isused to indicate that a first QoS target of a service cannot be met, andthe first QoS target includes a first guaranteed bit rate GBR; and aprocessing module, configured to: skip processing a QoS policy rule ofthe service if the receiving module receives, in a first preset time,second indication information sent by the SMF network element, where thesecond indication information is used to indicate that the first QoStarget can be met; or delete or modify a QoS policy rule of the serviceif the receiving module does not receive, in the first preset time, thesecond indication information sent by the SMF network element.

In a possible implementation, the processing module is furtherconfigured to: delete or modify the QoS policy rule of the service ifthe receiving module receives, in the first preset time, thirdindication information sent by the SMF network element, where the thirdindication information is used to indicate that the first QoS targetcannot be met.

In a possible implementation, the processing module is furtherconfigured to: determine, based on the first indication information, anoperation to be performed on the service, where the operation is thedeleting or modifying a QoS policy rule of the service, and a state ofthe operation is a to-be-performed state.

In a possible implementation, that the processing module modifies a QoSpolicy rule of the service includes: determining a second QoS target ofthe service based on QoS policy information, where the second QoS targetincludes a second GBR, and the QoS policy information includes at leastfirst QoS control information and second QoS control information.

The PCF network element further includes: a sending module, configuredto send the second QoS target to the SMF network element.

In a possible implementation, the QoS policy information furtherincludes priority information of the first QoS control information andpriority information of the second QoS control information; and that theprocessing module determines a second QoS target of the service based onQoS policy information includes: determining the second QoS target ofthe service based on the priority information of the first QoS controlinformation and the priority information of the second QoS controlinformation that are included in the QoS policy information.

In a possible implementation, that the processing module determines asecond QoS target of the service based on QoS policy informationincludes: determining the second QoS target of the service based onguaranteed bit flow GBR information of the first QoS control informationand GBR information of the second QoS control information that areincluded in the QoS policy information.

In a possible implementation, that the processing module determines asecond QoS target of the QoS flow based on QoS policy informationincludes: determining at least one third QoS target based on the firstQoS control information and the second QoS control information that areincluded in the QoS policy information, where the sending module isfurther configured to send the third QoS target to the SMF networkelement; and the receiving module is further configured to receive afourth QoS target sent by the SMF network element, where the fourth QoStarget is determined by the SMF network element based on a QoS targetthat can be met by an access network apparatus; and determining thesecond QoS target based on the fourth QoS target.

In a possible implementation, the receiving module is further configuredto receive a fifth QoS target sent by the SMF network element, where thefifth QoS target is determined by the SMF network element based on a QoStarget that can be met by an access network apparatus.

That the processing module determines a second QoS target of the servicebased on QoS policy information includes: determining the second QoStarget based on the fifth QoS target.

In a possible implementation, the receiving module is further configuredto receive at least two QoS requirements sent by an application functionAF network element.

The processing module is further configured to generate the QoS policyinformation based on the at least two QoS requirements.

An eleventh aspect of this application provides an application functionAF, including: a receiving module, configured to receive firstindication information sent by a policy control function PCF networkelement, where the first indication information is used to indicate thata first QoS target of a service cannot be met, and the first QoS targetincludes a first guaranteed bit rate GBR; and a processing module,configured to: skip processing a QoS requirement of the service if thereceiving module receives, in a first preset time, second indicationinformation sent by the PCF network element, where the second indicationinformation is used to indicate that the first QoS target can be met; ordelete or modify a QoS requirement of the service if the receivingmodule does not receive, in the first preset time, the second indicationinformation sent by the PCF network element.

In a possible implementation, the processing module is furtherconfigured to: delete or modify the QoS requirement of the service ifthe receiving module receives, in the first preset time, thirdindication information sent by the PCF network element, where the thirdindication information is used to indicate that the first QoS targetcannot be met.

In a possible implementation, the processing module is furtherconfigured to: determine, based on the first indication information, anoperation to be performed on the service, where the operation is thedeleting or modifying a QoS requirement of the service, and a state ofthe operation is a to-be-performed state.

In a possible implementation, that the processing module modifies a QoSrequirement of the service includes: determining a second QoS target ofthe service based on QoS policy information, where the second QoS targetincludes a second GBR, and the QoS policy information includes at leastfirst QoS requirement information and second QoS requirementinformation.

The AF network element further includes: a sending module, configured tosend the second QoS target to the PCF network element.

In a possible implementation, the QoS policy information furtherincludes priority information of the first QoS requirement informationand priority information of the second QoS requirement information; andthat the processing module determines a second QoS target of the servicebased on QoS policy information includes: determining the second QoStarget of the service based on the priority information of the first QoSrequirement information and the priority information of the second QoSrequirement information that are included in the QoS policy information.

In a possible implementation, that the processing module determines asecond QoS target of the service based on QoS policy informationincludes: determining the second QoS target of the service based onguaranteed bit rate GBR information of the first QoS requirementinformation and GBR information of the second QoS requirementinformation that are included in the QoS policy information.

In a possible implementation, that the processing module determines asecond QoS target of the QoS flow based on QoS policy informationincludes: determining at least one third QoS target based on the firstQoS requirement information and the second QoS requirement informationthat are included in the QoS policy information, where the sendingmodule is further configured to send the third QoS target to the PCFnetwork element; and the receiving module is further configured toreceive a fourth QoS target sent by the PCF network element, where thefourth QoS target is determined by the PCF network element based on aQoS target that can be met by an access network apparatus; anddetermining the second QoS target based on the fourth QoS target.

In a possible implementation, the receiving module is further configuredto receive a fifth QoS target sent by the PCF network element, where thefifth QoS target is determined by the PCF network element based on a QoStarget that can be met by an access network apparatus.

That the processing module determines a second QoS target of the servicebased on QoS policy information includes: determining the second QoStarget based on the fifth QoS target.

A twelfth aspect of this application provides an SMF network element,including: a receiving module, configured to receive first indicationinformation sent by an access network apparatus, where the firstindication information is used to indicate that a first QoS target of aQoS flow cannot be met, the first QoS target includes a first GFBR, andthe QoS flow is a flow on which same QoS processing is performed; aprocessing module, configured to determine a second QoS target of theQoS flow based on QoS policy information, where the second QoS targetincludes a second GFBR, and the QoS policy information includes at leastfirst QoS control information and second QoS control information; and asending module, configured to send the second QoS target to the accessnetwork apparatus.

In a possible implementation, the QoS policy information furtherincludes at least priority information of the first QoS controlinformation and priority information of the second QoS controlinformation; and the processing module is specifically configured to:determine the second QoS target of the QoS flow based on the priorityinformation of the first QoS control information and the priorityinformation of the second QoS control information that are included inthe QoS policy information.

In a possible implementation, the processing module is specificallyconfigured to: determine the second QoS target of the QoS flow based onguaranteed bit flow GBR information of the first QoS control informationand GBR information of the second QoS control information that areincluded in the QoS policy information.

In a possible implementation, the processing module is specificallyconfigured to: determine at least one third QoS target based on thefirst QoS control information and the second QoS control informationthat are included in the QoS policy information, where the sendingmodule is further configured to send the third QoS target to the accessnetwork apparatus; and the receiving module is further configured toreceive a fourth QoS target sent by the access network apparatus, wherethe fourth QoS target is determined by the access network apparatusbased on the third QoS target, and the fourth QoS target is a QoS targetthat can be met by the access network apparatus; and determine thesecond QoS target based on the fourth QoS target.

In a possible implementation, the sending module is further configuredto send at least two QoS targets of the QoS flow to the access networkapparatus based on the QoS policy information.

The receiving module is further configured to receive a fifth QoS targetsent by the access network apparatus, where the fifth QoS target is aQoS target that can be met by the access network apparatus, and thefifth QoS target is determined by the access network apparatus based onthe at least two QoS targets when the first QoS target of the QoS flowcannot be met.

The processing module is specifically configured to: determine thesecond QoS target based on the fifth QoS target.

In a possible implementation, the receiving module is further configuredto: receive the QoS policy information sent by a policy control functionPCF network element, where the QoS policy information is generated bythe PCF network element based on at least two QoS requirements sent byan application function AF network element.

A thirteenth aspect of this application provides a policy controlfunction PCF network element, including: a receiving module, configuredto receive first indication information sent by a session managementfunction SMF network element, where the first indication information isused to indicate that a first QoS target of a service cannot be met, andthe first QoS target includes a first guaranteed bit rate GBR; aprocessing module, configured to determine a second QoS target of theservice based on QoS policy information, where the second QoS targetincludes a second GBR, and the QoS policy information includes at leastfirst QoS control information and second QoS control information; and asending module, configured to send the second QoS target to the SMFnetwork element.

In a possible implementation, the QoS policy information furtherincludes priority information of the first QoS control information andpriority information of the second QoS control information; and theprocessing module is specifically configured to: determine the secondQoS target of the service based on the priority information of the firstQoS control information and the priority information of the second QoScontrol information that are included in the QoS policy information.

In a possible implementation, the processing module is specificallyconfigured to: determine the second QoS target of the service based onguaranteed bit flow GBR information of the first QoS control informationand GBR information of the second QoS control information that areincluded in the QoS policy information.

In a possible implementation, the processing module is specificallyconfigured to: determine at least one third QoS target based on thefirst QoS control information and the second QoS control informationthat are included in the QoS policy information, where the sendingmodule is further configured to send the third QoS target to the SMFnetwork element; and the receiving module is further configured toreceive a fourth QoS target sent by the SMF network element, where thefourth QoS target is determined by the SMF network element based on aQoS target that can be met by an access network apparatus; and determinethe second QoS target based on the fourth QoS target.

In a possible implementation, the receiving module is further configuredto receive a fifth QoS target sent by the SMF network element, where thefifth QoS target is determined by the SMF network element based on a QoStarget that can be met by an access network apparatus.

The processing module is specifically configured to: determine thesecond QoS target based on the fifth QoS target.

In a possible implementation, the receiving module is further configuredto: receive at least two QoS requirements sent by an applicationfunction AF network element.

The processing module is further configured to generate the QoS policyinformation based on the at least two QoS requirements.

A fourteenth aspect of this application provides an application functionAF network element, including: a receiving module, configured to receivefirst indication information sent by a policy control function PCFnetwork element, where the first indication information is used toindicate that a first QoS target of a service cannot be met, and thefirst QoS target includes a first guaranteed bit rate GBR; a processingmodule, configured to determine a second QoS target of the service basedon QoS policy information, where the second QoS target includes a secondGBR, and the QoS policy information includes at least first QoSrequirement information and second QoS requirement information; and asending module, configured to send the second QoS target to the PCFnetwork element.

In a possible implementation, the QoS policy information furtherincludes priority information of the first QoS requirement informationand priority information of the second QoS requirement information; andthe processing module is specifically configured to: determine thesecond QoS target of the service based on the priority information ofthe first QoS requirement information and the priority information ofthe second QoS requirement information that are included in the QoSpolicy information.

In a possible implementation, the processing module is specificallyconfigured to: determine the second QoS target of the service based onguaranteed bit rate GBR information of the first QoS requirementinformation and GBR information of the second QoS requirementinformation that are included in the QoS policy information.

In a possible implementation, the processing module is specificallyconfigured to: determine at least one third QoS target based on thefirst QoS requirement information and the second QoS requirementinformation that are included in the QoS policy information, where thesending module is further configured to send the third QoS target to thePCF network element; and the receiving module is further configured toreceive a fourth QoS target sent by the PCF network element, where thefourth QoS target is determined by the PCF network element based on aQoS target that can be met by an access network apparatus; and determinethe second QoS target based on the fourth QoS target.

In a possible implementation, the receiving module is further configuredto: receive a fifth QoS target sent by the PCF network element, wherethe fifth QoS target is determined by the PCF network element based on aQoS target that can be met by an access network apparatus.

The processing module is specifically configured to: determine thesecond QoS target based on the fifth QoS target.

A fifteenth aspect of this application provides a session managementfunction SMF network element, including: a receiver, configured toreceive first indication information sent by an access networkapparatus, where the first indication information is used to indicatethat a first QoS target of a QoS flow cannot be met, the first QoStarget includes a first guaranteed flow bit rate GFBR, and the QoS flowis a flow on which same QoS processing is performed; and a processor,configured to: skip processing the QoS flow if the receiver receives, ina first preset time, second indication information sent by the accessnetwork apparatus, where the second indication information is used toindicate that the first QoS target can be met; or delete or modify theQoS flow if the receiver module does not receive, in the first presettime, the second indication information sent by the access networkapparatus.

In a possible implementation, the processor is further configured todelete or modify the QoS flow if the receiver receives, in the firstpreset time, third indication information sent by the access networkapparatus, where the third indication information is used to indicatethat the first QoS target cannot be met.

In a possible implementation, the processor is further configured todetermine, based on the first indication information, an operation to beperformed on the QoS flow, where the operation is the deleting ormodifying the QoS flow, and a state of the operation is ato-be-performed state.

In a possible implementation, the SMF network element further includes atransmitter.

The processor is specifically configured to determine a second QoStarget of the QoS flow based on QoS policy information, where the secondQoS target includes a second GFBR, and the QoS policy informationincludes at least first QoS control information and second QoS controlinformation.

The transmitter is configured to send the second QoS target to theaccess network apparatus.

In a possible implementation, the QoS policy information furtherincludes at least priority information of the first QoS controlinformation and priority information of the second QoS controlinformation; and that the processor determines a second QoS target ofthe QoS flow based on QoS policy information includes: determining thesecond QoS target of the QoS flow based on the priority information ofthe first QoS control information and the priority information of thesecond QoS control information that are included in the QoS policyinformation.

In a possible implementation, that the processor determines a second QoStarget of the QoS flow based on QoS policy information includes:determining the second QoS target of the QoS flow based on guaranteedbit flow GBR information of the first QoS control information and GBRinformation of the second QoS control information that are included inthe QoS policy information.

In a possible implementation, that the processor determines a second QoStarget of the QoS flow based on QoS policy information includes:determining at least one third QoS target based on the first QoS controlinformation and the second QoS control information that are included inthe QoS policy information, where the transmitter is further configuredto send the third QoS target to the access network apparatus; and thereceiver is further configured to receive a fourth QoS target sent bythe access network apparatus, where the fourth QoS target is determinedby the access network apparatus based on the third QoS target, and thefourth QoS target is a QoS target that can be met by the access networkapparatus; and determining the second QoS target based on the fourth QoStarget.

In a possible implementation, the transmitter is further configured tosend at least two QoS targets of the QoS flow to the access networkapparatus based on the QoS policy information.

The receiver is further configured to receive a fifth QoS target sent bythe access network apparatus, where the fifth QoS target is a QoS targetthat can be met by the access network apparatus, and the fifth QoStarget is determined by the access network apparatus based on the atleast two QoS targets when the first QoS target of the QoS flow cannotbe met.

That the processor determines a second QoS target of the QoS flow basedon QoS policy information includes: determining the second QoS targetbased on the fifth QoS target.

In a possible implementation, the receiver is further configured to:receive the QoS policy information sent by a policy control function PCFnetwork element, where the QoS policy information is generated by thePCF network element based on at least two QoS requirements sent by anapplication function AF network element.

A sixteenth aspect of this application provides an access networkapparatus, including: a transmitter, configured to send first indicationinformation to a session management function SMF network element, wherethe first indication information is used to indicate that a first QoStarget of a QoS flow of user equipment UE cannot be met, the first QoStarget includes a first guaranteed flow bit rate GFBR, and the first QoSflow is a flow on which same QoS processing is performed.

The transmitter is further configured to: if the first QoS target can bemet in a second preset time, send second indication information to theSMF network element, where the second indication information is used toindicate that the first QoS target can be met.

In a possible implementation, the transmitter is further configured to:if the first QoS target cannot be met in the second preset time, sendthird indication information to the SMF network element, where the thirdindication information is used to indicate that the first QoS targetcannot be met.

In a possible implementation, the transmitter is further configured to:if the access network apparatus does not receive a modificationprocedure or deletion procedure that is for the QoS flow and that issent by the SMF network element, send a deletion request for the QoSflow to the SMF network element.

In a possible implementation, the access network apparatus furtherincludes: a processor, configured to delete the second preset time ifthe access network apparatus receives, in the second preset time, adeletion or modification request that is for the QoS flow and that issent by the SMF network element.

In a possible implementation, the access network apparatus furtherincludes: a receiver, configured to receive a second QoS target sent bythe SMF network element, where the second QoS target includes a secondGFBR; and a processor, configured to modify the QoS flow based on thesecond QoS target.

In a possible implementation, before receiving the second QoS targetsent by the SMF network element, the receiver is further configured toreceive at least one third QoS target sent by the SMF network element.

The access network apparatus further includes: a processor, configuredto determine a fourth QoS target based on the third QoS target, wherethe fourth QoS target is a QoS target that can be met by the accessnetwork apparatus.

The transmitter is further configured to send the fourth QoS target tothe SMF network element.

In a possible implementation, the access network apparatus furtherincludes: a receiver, configured to receive at least two QoS targets ofthe QoS flow that are sent by the SMF network element; and a processor,configured to: when the first QoS target of the QoS flow cannot be met,select a fifth QoS target from the at least two QoS targets, where thefifth QoS target is a QoS target that can be met by the access networkapparatus.

The transmitter is further configured to send the fifth QoS target tothe SMF network element, so that the SMF network element determines thesecond QoS target based on the fifth QoS target.

A seventeenth aspect of this application provides a policy controlfunction PCF network element, including: a receiver, configured toreceive first indication information sent by a session managementfunction SMF network element, where the first indication information isused to indicate that a first QoS target of a service cannot be met, andthe first QoS target includes a first guaranteed bit rate GBR; and aprocessor, configured to: skip processing a QoS policy rule of theservice if the receiver receives, in a first preset time, secondindication information sent by the SMF network element, where the secondindication information is used to indicate that the first QoS target canbe met; or delete or modify a QoS policy rule of the service if thereceiver does not receive, in the first preset time, the secondindication information sent by the SMF network element.

In a possible implementation, the processor is further configured to:delete or modify the QoS policy rule of the service if the receiverreceives, in the first preset time, third indication information sent bythe SMF network element, where the third indication information is usedto indicate that the first QoS target cannot be met.

In a possible implementation, the processor is further configured to:determine, based on the first indication information, an operation to beperformed on the service, where the operation is the deleting ormodifying a QoS policy rule of the service, and a state of the operationis a to-be-performed state.

In a possible implementation, that the processor modifies a QoS policyrule of the service includes: determining a second QoS target of theservice based on QoS policy information, where the second QoS targetincludes a second GBR, and the QoS policy information includes at leastfirst QoS control information and second QoS control information.

The PCF network element further includes: a transmitter, configured tosend the second QoS target to the SMF network element.

In a possible implementation, the QoS policy information furtherincludes priority information of the first QoS control information andpriority information of the second QoS control information; and that theprocessor determines a second QoS target of the service based on QoSpolicy information includes: determining the second QoS target of theservice based on the priority information of the first QoS controlinformation and the priority information of the second QoS controlinformation that are included in the QoS policy information.

In a possible implementation, that the processor determines a second QoStarget of the service based on QoS policy information includes:determining the second QoS target of the service based on guaranteed bitflow GBR information of the first QoS control information and GBRinformation of the second QoS control information that are included inthe QoS policy information.

In a possible implementation, that the processor determines a second QoStarget of the QoS flow based on QoS policy information includes:determining at least one third QoS target based on the first QoS controlinformation and the second QoS control information that are included inthe QoS policy information, where the transmitter is further configuredto send the third QoS target to the SMF network element; and thereceiver is further configured to receive a fourth QoS target sent bythe SMF network element, where the fourth QoS target is determined bythe SMF network element based on a QoS target that can be met by anaccess network apparatus; and determining the second QoS target based onthe fourth QoS target.

In a possible implementation, the receiver is further configured toreceive a fifth QoS target sent by the SMF network element, where thefifth QoS target is determined by the SMF network element based on a QoStarget that can be met by an access network apparatus.

That the processor determines a second QoS target of the service basedon QoS policy information includes: determining the second QoS targetbased on the fifth QoS target.

In a possible implementation, the receiver is further configured toreceive at least two QoS requirements sent by an application function AFnetwork element.

The processor is further configured to generate the QoS policyinformation based on the at least two QoS requirements.

An eighteenth aspect of this application provides an applicationfunction AF, including: a receiver, configured to receive firstindication information sent by a policy control function PCF networkelement, where the first indication information is used to indicate thata first QoS target of a service cannot be met, and the first QoS targetincludes a first guaranteed bit rate GBR; and a processor, configuredto: skip processing a QoS requirement of the service if the receiverreceives, in a first preset time, second indication information sent bythe PCF network element, where the second indication information is usedto indicate that the first QoS target can be met; or delete or modify aQoS requirement of the service if the receiver does not receive, in thefirst preset time, the second indication information sent by the PCFnetwork element.

In a possible implementation, the processor is further configured to:delete or modify the QoS requirement of the service if the receiverreceives, in the first preset time, third indication information sent bythe PCF network element, where the third indication information is usedto indicate that the first QoS target cannot be met.

In a possible implementation, the processor is further configured to:determine, based on the first indication information, an operation to beperformed on the service, where the operation is the deleting ormodifying a QoS requirement of the service, and a state of the operationis a to-be-performed state.

In a possible implementation, that the processor modifies a QoSrequirement of the service includes: determining a second QoS target ofthe service based on QoS policy information, where the second QoS targetincludes a second GBR, and the QoS policy information includes at leastfirst QoS requirement information and second QoS requirementinformation.

The AF network element further includes: a transmitter, configured tosend the second QoS target to the PCF network element.

In a possible implementation, the QoS policy information furtherincludes priority information of the first QoS requirement informationand priority information of the second QoS requirement information; andthat the processor determines a second QoS target of the service basedon QoS policy information includes: determining the second QoS target ofthe service based on the priority information of the first QoSrequirement information and the priority information of the second QoSrequirement information that are included in the QoS policy information.

In a possible implementation, that the processor determines a second QoStarget of the service based on QoS policy information includes:determining the second QoS target of the service based on guaranteed bitrate GBR information of the first QoS requirement information and GBRinformation of the second QoS requirement information that are includedin the QoS policy information.

In a possible implementation, that the processor determines a second QoStarget of the QoS flow based on QoS policy information includes:determining at least one third QoS target based on the first QoSrequirement information and the second QoS requirement information thatare included in the QoS policy information, where the transmitter isfurther configured to send the third QoS target to the PCF networkelement; and the receiver is further configured to receive a fourth QoStarget sent by the PCF network element, where the fourth QoS target isdetermined by the PCF network element based on a QoS target that can bemet by an access network apparatus; and determining the second QoStarget based on the fourth QoS target.

In a possible implementation, the receiver is further configured toreceive a fifth QoS target sent by the PCF network element, where thefifth QoS target is determined by the PCF network element based on a QoStarget that can be met by an access network apparatus.

That the processor determines a second QoS target of the service basedon QoS policy information includes: determining the second QoS targetbased on the fifth QoS target.

A nineteenth aspect of this application provides an SMF network element,including: a receiver, configured to receive first indicationinformation sent by an access network apparatus, where the firstindication information is used to indicate that a first QoS target of aQoS flow cannot be met, the first QoS target includes a first GFBR, andthe QoS flow is a flow on which same QoS processing is performed; aprocessor, configured to determine a second QoS target of the QoS flowbased on QoS policy information, where the second QoS target includes asecond GFBR, and the QoS policy information includes at least first QoScontrol information and second QoS control information; and atransmitter, configured to send the second QoS target to the accessnetwork apparatus.

In a possible implementation, the QoS policy information furtherincludes at least priority information of the first QoS controlinformation and priority information of the second QoS controlinformation; and the processor is specifically configured to: determinethe second QoS target of the QoS flow based on the priority informationof the first QoS control information and the priority information of thesecond QoS control information that are included in the QoS policyinformation.

In a possible implementation, the processor is specifically configuredto: determine the second QoS target of the QoS flow based on guaranteedbit flow GBR information of the first QoS control information and GBRinformation of the second QoS control information that are included inthe QoS policy information.

In a possible implementation, the processor is specifically configuredto: determine at least one third QoS target based on the first QoScontrol information and the second QoS control information that areincluded in the QoS policy information, where the transmitter is furtherconfigured to send the third QoS target to the access network apparatus;and the receiver is further configured to receive a fourth QoS targetsent by the access network apparatus, where the fourth QoS target isdetermined by the access network apparatus based on the third QoStarget, and the fourth QoS target is a QoS target that can be met by theaccess network apparatus; and determine the second QoS target based onthe fourth QoS target.

In a possible implementation, the transmitter is further configured tosend at least two QoS targets of the QoS flow to the access networkapparatus based on the QoS policy information.

The receiver is further configured to receive a fifth QoS target sent bythe access network apparatus, where the fifth QoS target is a QoS targetthat can be met by the access network apparatus, and the fifth QoStarget is determined by the access network apparatus based on the atleast two QoS targets when the first QoS target of the QoS flow cannotbe met.

The processor is specifically configured to: determine the second QoStarget based on the fifth QoS target.

In a possible implementation, the receiver is further configured to:receive the QoS policy information sent by a policy control function PCFnetwork element, where the QoS policy information is generated by thePCF network element based on at least two QoS requirements sent by anapplication function AF network element.

A twentieth aspect of this application provides a policy controlfunction PCF network element, including: a receiver, configured toreceive first indication information sent by a session managementfunction SMF network element, where the first indication information isused to indicate that a first QoS target of a service cannot be met, andthe first QoS target includes a first guaranteed bit rate GBR; aprocessor, configured to determine a second QoS target of the servicebased on QoS policy information, where the second QoS target includes asecond GBR, and the QoS policy information includes at least first QoScontrol information and second QoS control information; and atransmitter, configured to send the second QoS target to the SMF networkelement.

In a possible implementation, the QoS policy information furtherincludes priority information of the first QoS control information andpriority information of the second QoS control information; and theprocessor is specifically configured to: determine the second QoS targetof the service based on the priority information of the first QoScontrol information and the priority information of the second QoScontrol information that are included in the QoS policy information.

In a possible implementation, the processor is specifically configuredto: determine the second QoS target of the service based on guaranteedbit flow GBR information of the first QoS control information and GBRinformation of the second QoS control information that are included inthe QoS policy information.

In a possible implementation, the processor is specifically configuredto: determine at least one third QoS target based on the first QoScontrol information and the second QoS control information that areincluded in the QoS policy information, where the transmitter is furtherconfigured to send the third QoS target to the SMF network element; andthe receiver is further configured to receive a fourth QoS target sentby the SMF network element, where the fourth QoS target is determined bythe SMF network element based on a QoS target that can be met by anaccess network apparatus; and determine the second QoS target based onthe fourth QoS target.

In a possible implementation, the receiver is further configured toreceive a fifth QoS target sent by the SMF network element, where thefifth QoS target is determined by the SMF network element based on a QoStarget that can be met by an access network apparatus.

The processor is specifically configured to: determine the second QoStarget based on the fifth QoS target.

In a possible implementation, the receiver is further configured to:receive at least two QoS requirements sent by an application function AFnetwork element.

The processor is further configured to generate the QoS policyinformation based on the at least two QoS requirements.

A twenty-first aspect of this application provides an applicationfunction AF network element, including: a receiver, configured toreceive first indication information sent by a policy control functionPCF network element, where the first indication information is used toindicate that a first QoS target of a service cannot be met, and thefirst QoS target includes a first guaranteed bit rate GBR; a processor,configured to determine a second QoS target of the service based on QoSpolicy information, where the second QoS target includes a second GBR,and the QoS policy information includes at least first QoS requirementinformation and second QoS requirement information; and a transmitter,configured to send the second QoS target to the PCF network element.

In a possible implementation, the QoS policy information furtherincludes priority information of the first QoS requirement informationand priority information of the second QoS requirement information; andthe processor is specifically configured to: determine the second QoStarget of the service based on the priority information of the first QoSrequirement information and the priority information of the second QoSrequirement information that are included in the QoS policy information.

In a possible implementation, the processor is specifically configuredto: determine the second QoS target of the service based on guaranteedbit rate GBR information of the first QoS requirement information andGBR information of the second QoS requirement information that areincluded in the QoS policy information.

In a possible implementation, the processor is specifically configuredto: determine at least one third QoS target based on the first QoSrequirement information and the second QoS requirement information thatare included in the QoS policy information, where the transmitter isfurther configured to send the third QoS target to the PCF networkelement; and the receiver is further configured to receive a fourth QoStarget sent by the PCF network element, where the fourth QoS target isdetermined by the PCF network element based on a QoS target that can bemet by an access network apparatus; and determine the second QoS targetbased on the fourth QoS target.

In a possible implementation, the receiver is further configured to:receive a fifth QoS target sent by the PCF network element, where thefifth QoS target is determined by the PCF network element based on a QoStarget that can be met by an access network apparatus.

The processor is specifically configured to: determine the second QoStarget based on the fifth QoS target.

A twenty-second aspect of this application provides a computer readablestorage medium. The computer readable storage medium stores aninstruction. When the instruction is executed, a computer is enabled toperform the QoS flow control method according to the first aspect ofthis application.

A twenty-third aspect of this application provides a computer readablestorage medium. The computer readable storage medium stores aninstruction. When the instruction is executed, a computer is enabled toperform the QoS flow control method according to the second aspect ofthis application.

A twenty-fourth aspect of this application provides a computer readablestorage medium. The computer readable storage medium stores aninstruction. When the instruction is executed, a computer is enabled toperform the QoS flow control method according to the third aspect ofthis application.

A twenty-fifth aspect of this application provides a computer readablestorage medium. The computer readable storage medium stores aninstruction. When the instruction is executed, a computer is enabled toperform the QoS flow control method according to the fourth aspect ofthis application.

A twenty-sixth aspect of this application provides a computer readablestorage medium. The computer readable storage medium stores aninstruction. When the instruction is executed, a computer is enabled toperform the QoS flow control method according to the fifth aspect ofthis application.

A twenty-seventh aspect of this application provides a computer readablestorage medium. The computer readable storage medium stores aninstruction. When the instruction is executed, a computer is enabled toperform the QoS flow control method according to the sixth aspect ofthis application.

A twenty-eighth aspect of this application provides a computer readablestorage medium. The computer readable storage medium stores aninstruction. When the instruction is executed, a computer is enabled toperform the QoS flow control method according to the seventh aspect ofthis application.

A twenty-ninth aspect of this application provides a system chip,including a processing unit and a communications unit. The processingunit may execute a computer instruction, so that the system chipperforms the method according to any one of the first aspect to theseventh aspect.

According to the QoS flow control method and the apparatus that areprovided in this application, the SMF network element receives the firstindication information sent by the access network apparatus, where thefirst indication information is used to indicate that the first QoStarget of the QoS flow cannot be met; and then the SMF network elementdetermines whether the SMF network element receives, in the first presettime, the second indication information sent by the access networkapparatus, where the second indication information is used to indicatethat the first QoS target can be met. If the SMF network elementreceives the second indication information, the SMF network element doesnot process the QoS flow. If the SMF network element does not receivethe second indication information, the SMF network element deletes ormodifies the QoS flow. In the method, when the QoS target of the QoSflow cannot be met, the SMF network element does not immediately deleteor modify the QoS flow. Instead, the SMF network element deletes ormodifies the QoS flow only when the QoS target of the QoS flow stillcannot be met within a delay of the first preset time, to avoid aproblem that a QoS flow service cannot be served or quality of serviceof a service is reduced because the SMF network element immediatelydeletes or modifies the QoS flow when resources of the access networkapparatus are temporarily short.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a network architecture to which thisapplication is applicable;

FIG. 2 is a schematic diagram of a 5G network architecture;

FIG. 3 is a schematic diagram of a 5G network architecture based on aservice-based interface in a non-roaming scenario;

FIG. 4 is a schematic diagram of a 5G network architecture based on aservice-based interface in a local breakout roaming scenario;

FIG. 5 is a schematic diagram of a 5G network architecture based on areference point in a local breakout roaming scenario;

FIG. 6 is a schematic diagram of a 5G network architecture based on aservice-based interface in a home routed roaming scenario;

FIG. 7 is a schematic diagram of a 5G network architecture based on areference point in a home routed roaming scenario;

FIG. 8 is a flowchart of a QoS flow control method according toEmbodiment 1 of this application;

FIG. 9 is a flowchart of a QoS flow control method according toEmbodiment 2 of the present invention;

FIG. 10 is a flowchart of a QoS flow control method according toEmbodiment 3 of this application;

FIG. 11 is a flowchart of a QoS flow control method according toEmbodiment 4 of this application;

FIG. 12 is a signaling flowchart of a QoS flow control method accordingto Embodiment 5 of this application;

FIG. 13A and FIG. 13B are a signaling flowchart of a QoS flow controlmethod according to Embodiment 6 of this application;

FIG. 14 is a signaling flowchart of a QoS flow control method accordingto Embodiment 7 of this application;

FIG. 15 is a signaling flowchart of a QoS flow control method accordingto Embodiment 8 of this application;

FIG. 16 is a flowchart of a QoS flow control method according toEmbodiment 9 of this application;

FIG. 17 is a flowchart of a QoS flow control method according toEmbodiment 10 of the present invention;

FIG. 18A and FIG. 18B are a signaling flowchart of a QoS flow controlmethod according to Embodiment 11 of this application;

FIG. 19 is a flowchart of a QoS flow control method according toEmbodiment 12 of this application;

FIG. 20 is a flowchart of a QoS flow control method according toEmbodiment 13 of the present invention;

FIG. 21A and FIG. 21B are a signaling flowchart of a QoS flow controlmethod according to Embodiment 14 of this application;

FIG. 22 is a schematic structural diagram of an SMF network elementaccording to Embodiment 19 of this application;

FIG. 23 is a schematic structural diagram of an access network apparatusaccording to Embodiment 20 of this application;

FIG. 24 is a schematic structural diagram of a PCF network elementaccording to Embodiment 21 of this application; and

FIG. 25 is a schematic structural diagram of an AF network elementaccording to Embodiment 22 of this application.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

This application provides a QoS flow (QoS flow) control method. Themethod in this application may be applied to a 5G system, or may beapplied to an evolved packet system (EPS). FIG. 1 is a schematic diagramof a network architecture to which this application is applicable. Asshown in FIG. 1 , the network architecture includes UE, an accessnetwork (AN), a core network, and a data network (DN). The accessnetwork apparatus is mainly configured to implement functions such as awireless physical layer function, resource scheduling, radio resourcemanagement, radio access control, and mobility management. The corenetwork device may include a management device and a gateway device. Themanagement device is mainly configured to perform device registration,security authentication, mobility management, location management, andthe like on a terminal device. The gateway device is mainly configuredto: establish a channel with the terminal device, and forward a datapacket between the terminal device and an external data network on thechannel. The data network may include a network device (for example, adevice such as a server or a router), and the data network is mainlyconfigured to provide a plurality of data service services for theterminal device. It should be noted that FIG. 1 is merely a diagram ofan example of the architecture. In addition to the function units shownin FIG. 1 , the network architecture may include another function unit.This is not limited in the embodiments of the present invention.

The network architecture may be a 5G network architecture. FIG. 2 is aschematic diagram of a 5G network architecture. The 5G system is alsoreferred to as a new radio communications system, a new accesstechnology (NR), or a next generation mobile communications system.

An access network (AN) in the 5G system may be a radio access network((R)AN), and an (R)AN device in the 5G system may include a plurality of5G-(R)AN nodes. The 5G-(R)AN nodes may include an access point (AP) in anon-3GPP access network such as a Wi-Fi network, a next generation NodeB(including a new radio NodeB (NR NodeB, gNB), a next generation evolvedNodeB (NG-eNB), a gNB in which a central unit (CU) is separated from adistributed unit (DU), and the like, which may be collectively referredto as a next generation radio access network node (NG-RAN node)), atransmission reception point (TRP), a transmission point (TP), oranother node.

As shown in FIG. 2 , a 5G core network (5G core/new generation core,5GC/NGC) includes a plurality of function units such as an access andmobility management function (AMF) network element, a session managementfunction (SMF) network element, a user plane function (UPF) networkelement, an authentication server function (AUSF) network element, apolicy control function (PCF) network element, an application function(AF) network element, a unified data management (UDM) function networkelement, and a network slice selection function (NSSF) network element.

The AMF network element is mainly responsible for services such asmobility management and access management. The SMF network element ismainly responsible for session management, UE address management andassignment, a dynamic host configuration protocol function, selectionand control of a user plane function, and the like. The UPF is mainlyresponsible for functions related to external connection to a datanetwork (DN), user plane data packet routing and forwarding, packetfiltering, quality of service (QoS) control, and the like. The AUSF ismainly responsible for an authentication function of the terminaldevice, and the like. The PCF network element is mainly responsible forproviding a unified policy framework for network behavior management,providing a policy rule of a control plane function, obtainingregistration information related to a policy decision, and the like. Itshould be noted that these function units may work independently, or maybe combined together to implement some control functions, for example,access control and mobility management functions such as accessauthentication, security encryption, and location registration of theterminal device, and session management functions such as establishment,release, and change of a user plane transmission path.

The function units in the 5GC may communicate with each other through anext generation (NG) network interface. For example, the UE may transmita control plane message with the AMF network element through an NGinterface 1 (N1 for short). The RAN device may establish a user planedata transmission channel with the UPF through an NG interface 3 (N3 forshort). The AN/RAN device may establish a control plane signalingconnection to the AMF network element through an NG interface 2 (N2 forshort). The UPF may exchange information with the SMF network elementthrough an NG interface 4 (N4 for short). The UPF may exchange userplane data with the data network DN through an NG interface 6 (N6 forshort). The AMF network element may exchange information with the SMFnetwork element through an NG interface 11 (N11 for short). The SMFnetwork element may exchange information with the PCF network elementthrough an NG interface 7 (N7 for short). The AMF network element mayexchange information with the AUSF through an NG interface 12 (N12 forshort). It should be noted that FIG. 2 is merely a diagram of an exampleof the architecture. In addition to the function units shown in FIG. 2 ,the network architecture may include another function unit.

The network architecture shown in FIG. 2 is a network architecture basedon a reference point, and the network architecture is a networkarchitecture in a non-roaming scenario. Certainly, the method in thisapplication may also be applied to a roaming scenario, and the networkarchitecture is not limited to the network architecture based on thereference point, or may be a network architecture based on aservice-based interface.

FIG. 3 is a schematic diagram of a 5G network architecture based on aservice-based interface in a non-roaming scenario. As shown in FIG. 3 ,in the scenario based on the service-based interface, the core networkin the 5G system further includes an NEF network element and an NRFnetwork element. In the scenario based on the service-based interface,some network elements in the 5G core network are connected by using abus. As shown in FIG. 3 , the AUSF network element, the AMF networkelement, the SMF network element, the AF network element, the UDM, thePCF network element, the network repository function (NRF) networkelement, the network exposure function (NEF) network element, and theNSSF network element are interconnected by using a bus. When the networkelements are interconnected by using the bus, a service-based interfaceis used. For example, the AUSF network element is connected to the busthrough an interface Nausf, the AMF network element is connected to thebus through an interface Namf, the SMF network element is connected tothe bus through an interface Nsmf, the AF network element is connectedto the bus through an NAF network element interface, the UDM isconnected to the bus through an interface Nudm, the PCF network elementis connected to the bus through an NPCF network element interface, theNRF is connected to the bus through an interface Nnrf, the NEF isconnected to the bus through an interface Nnef, and the NSSF isconnected to the bus through an interface Nnssf.

According to a roaming service access policy used by a mobile terminal,there are two roaming modes: home-routed roaming access and localbreakout roaming access. The home routed roaming access means that aroaming subscriber accesses a home network through a gateway (or anotherwith a same function as that of the gateway) of the home network toobtain a service provided by the home network. The local breakoutroaming access means that a roaming subscriber accesses a visitednetwork through a gateway of the visited network to obtain acorresponding service. A provider of the service may be the homenetwork, or may be the visited network.

FIG. 4 is a schematic diagram of a 5G network architecture based on aservice-based interface in a local breakout roaming scenario. As shownin FIG. 4 , a visited public land mobile network (VPLMN) is connected toan hSEEP in a home public land mobile network (HPLMN) by using a vSEEP,and the vSEEP and hSEEP are connected through an interface N32. RoamedUE accesses a DN in the VPLMN.

FIG. 5 is a schematic diagram of a 5G network architecture based on areference point in a local breakout roaming scenario. As shown in FIG. 5, a visited PCF (visited PCF, vPCF) network element in a VPLMN isconnected to a home PCF (home PCF, hPCF) network element in an HPLMNthrough an interface N24, an AMF network element in the VPLMN isconnected to a UDM network element in the HPLMN through an interface N8,the AMF network element in the VPLMN is connected to an AUSF networkelement in the HPLMN through an interface N12, and an SMF networkelement in the VPLMN is connected to the UDM network element in theHPLMN through an interface N10. Roamed UE accesses a DN in the VPLMN.

FIG. 6 is a schematic diagram of a 5G network architecture based on aservice-based interface in a home routed roaming scenario. Differentfrom the architecture shown in FIG. 4 , in the architecture shown inFIG. 6 , a VPLMN is connected to an hSEEP in an HPLMN by using a vSEEP,a UPF network element in the VPLMN is connected to a UPF network elementin the HPLMN through an interface N9, and the UPF network element in theHPLMN is connected to a DN, so that roamed UE accesses the DN in theHPLMN.

FIG. 7 is a schematic diagram of a 5G network architecture based on areference point in a home routed roaming scenario. As shown in FIG. 7 ,a vPCF network element in a VPLMN is connected to an hPCF networkelement in an HPLMN through an interface N24, an AMF network element inthe VPLMN is connected to a UDM in the HPLMN through an interface N8,the AMF network element in the VPLMN is connected to an AUSF in theHPLMN through an interface N12, a vSMF network element in the VPLMN isconnected to an hSMF network element in the HPLMN through an interfaceN16, a vNSSF in the VPLMN is connected to an hNSSF interface in theHPLMN through an interface N31, a UPF in the VPLMN is connected to a UPFinterface in the HPLMN through an interface N9, and the UPF networkelement in the HPLMN is connected to a DN, so that roamed UE accessesthe DN in the HPLMN.

When the method in this application is applied to an LTE system, thecore network is an evolved packet core EPC network, and includes amobility management entity (MME), a packet data network gateway (packetdata network gateway, P-GW), a serving gateway (S-GW), a home networkserver (HSS), and the like. The HSS is configured to store usersubscription information, including user service information,authentication information, location management information, and thelike. The MME is responsible for functions such as terminal accesscontrol, mobility management, session management, and network elementselection (for example, S-GW/P-GW selection). The S-GW is a mobilityanchor for handover between eNBs, and is responsible for functions suchas routing and forwarding of user plane data. The P-GW is responsiblefor functions such as IP address assignment, packet data filtering, ratecontrol, charging rule execution, and lawful interception.

The UE mentioned in this application may be a mobile phone or acomputer, or may be a cellular phone, a cordless phone, a sessioninitiation protocol (SIP) phone, a smartphone, a wireless local loop(WLL) station, a personal digital assistant (PDA), a computer, a laptopcomputer, a handheld communications device, a handheld computing device,a satellite wireless device, a wireless modem card, a television set-topbox (STB), a vehicle-mounted device, a wearable device, a smart homedevice, another device configured to perform communication in a wirelesssystem, or the like.

Based on the foregoing network architecture, this application provides aQoS flow control method. The method in this application is applied to aguaranteed bit rate QoS flow (GBR QoS flow), and UE or a network device(including an AN device and a core network device) processes, in a samemanner, data packets included in a same QoS flow. The QoS flow isidentified by using a QoS flow identifier (QFI). Whether a QoS flow is aGBR QoS flow or a non-GBR QoS flow is determined by a corresponding QoSprofile.

A QoS profile of the GBR QoS flow needs to include the following QoSparameters: a 5QI, an allocation and retention priority (ARP), aguaranteed flow bit flow (GFBR), and a maximum flow bit rate (MFBR).Optionally, the QoS profile of the GBR QoS flow further includesnotification control. The GBR QoS flows include, based on whether theQoS profile includes notification control, a GRB QoS flow that requiresnotification control and a GBR QoS flow that does not requirenotification control. For the GBR QoS flow that requires notificationcontrol, when an access network apparatus detects that a correspondingQoS flow resource cannot be met, the access network apparatus notifiesan SMF network element of the event. Further, the SMF network elementmay initiate a QoS flow deletion or modification procedure.

5QI: The 5QI is a scalar used to index a 5G QoS characteristic. The 5QIsinclude a standardized 5QI, a preconfigured 5QI, and a dynamicallyallocated 5QI. The standardized 5QIs are in a one-to-one correspondencewith a group of standardized 5G QoS characteristic values. A 5G QoScharacteristic value corresponding to the preconfigured 5QI ispreconfigured in the access network apparatus. A 5G QoS characteristiccorresponding to the dynamically allocated 5QI is included in the QoSprofile and sent to the access network apparatus.

ARP: The ARP includes a priority level, a preemption capability, and apreemption vulnerability.

RQA: The RQA is used to instruct a service transmitted by using acorresponding QoS flow to use reversed QoS.

Notification control: Notification control is used to indicate whetherthe AN notifies a network in a use time of the QoS flow when the GFBRcannot be met.

GFBR: The GFBR represents a guaranteed bit rate provided for the GBR QoSflow.

MFBR: The MFBR is used to limit a bit rate provided for the GBR QoSflow, namely, a maximum bit rate provided for the GBR QoS flow. If thebit rate is exceeded, a data packet can be discarded.

The GBR QoS flow may be controlled in a signaling-based manner. Acontrol manner is as follows: If an SMF network element determines,according to a local policy or a policy control and charging (PCC) rulesent by a PCF network element, to establish a QoS flow, the SMF networkelement sends SDF information to a UPF, where the SDF informationincludes QoS control information; sends a QoS profile of the QoS flow toan AN by using an AMF network element; and sends a QoS rule to UE byusing the AMF network element and the AN, where the QoS rule includesthe QoS control information.

The QoS flow is established between the UE, the AN, and the UPF. The ANestablishes or modifies a data radio bearer (DRB) over an air interfacebased on the QoS profile, and stores a binding relationship between theQoS flow and the DBR. After the QoS flow is bound to the DBR, subsequentdownlink data processing and uplink data processing are as follows.

Downlink data processing: When receiving a downlink data packet, the UPFperforms QoS control based on the SDF information sent by the SMFnetwork element, and adds a QFI to a data packet header. When receivinga downlink data packet, the AN places the data packet over acorresponding DRB for transmission based on the QFI in the packet headerand a binding relationship between a corresponding QoS flow and the DRB.

Uplink data processing: When determining to send an uplink data packet,the UE determines a QoS flow according to a QoS rule, adds a QFI to apacket header, and places the data packet over a corresponding DRB fortransmission based on a binding relationship between the QoS flow andthe DBR. When receiving an uplink data packet, the AN adds a QFI to adata packet header between the AN and the UPF based on a QFI in a packetheader of the uplink data packet. When receiving a data packet sent bythe AN, the UPF verifies whether the data packet is transmitted by usinga correct QoS flow.

Based on the foregoing network architecture, this application provides aQoS flow control method, to resolve a prior-art problem that a servicecannot be served or quality of service of a service is reduced becausewhen resources of an access network apparatus are temporarily short, anSMF network element immediately deletes or modifies a QoS flow whenreceiving indication information indicating that a QoS target cannot bemet. Same content in the following embodiments of this application maybe mutually referenced.

FIG. 8 is a flowchart of a QoS flow control method according toEmbodiment 1 of this application. As shown in FIG. 8 , the methodprovided in this embodiment includes the following steps.

Step S101: An SMF network element receives first indication informationsent by an access network apparatus, where the first indicationinformation is used to indicate that a first QoS target of a QoS flowcannot be met, the first QoS target includes a first GFBR, and the QoSflow is a flow on which same QoS processing is performed.

The QoS flow is a flow on which same QoS processing is performed, to bespecific, same transmission processing is performed on services usingthe QoS flow. During running of the QoS flow, the access networkapparatus detects whether the first QoS target of the QoS flow can bemet. The first QoS target is a QoS target of the QoS flow, and the firstQoS target includes a GFBR. Optionally, the first QoS target furtherincludes a data packet processing requirement such as a first MFBR or a5QI. In a manner, when the access network apparatus detects that thefirst QoS target cannot be met, and optionally, a profile of the QoSflow includes notification control, the access network apparatus sendsthe first indication information to the SMF network element. In anothermanner, when the access network apparatus detects that the first QoStarget cannot be met, the access network apparatus sends the firstindication information to the SMF network element regardless of whethera profile of the QoS flow includes notification control.

The first QoS target is QoS control information that is of the QoS flowand that is determined by the SMF network element based on QoS policyinformation provided by a PCF network element or local QoS policyinformation.

The SMF network element establishes the QoS flow for UE based on thefirst QoS target. The QoS policy information may include one piece or atleast two pieces of QoS control information. When the QoS policyinformation includes one piece of QoS control information, the SMFnetwork element determines the first QoS target based on the QoS controlinformation. Optionally, when the QoS policy information may include atleast two pieces of QoS control information, the SMF network elementselects one piece of QoS control information from the at least twopieces of QoS control information, and determines the first QoS targetbased on the selected QoS control information.

When the QoS policy information includes the at least two pieces of QoScontrol information, the QoS policy information may include one QoSpolicy rule or at least two QoS policy rules. When the QoS policyinformation includes one QoS policy rule, the QoS policy includes atleast two pieces of QoS control information. When the QoS policyinformation includes at least two QoS policy rules, in a manner, eachQoS policy rule includes one piece of QoS control information; inanother manner, each QoS policy rule includes at least two pieces of QoScontrol information; and in still another manner, some QoS policy rulesinclude one piece of QoS control information, and some QoS policy rulesinclude two pieces of QoS control information.

Optionally, the QoS policy information further includes priorityinformation of each piece of QoS control information. When determiningthe first QoS target, the SMF network element may determine the firstQoS target based on the priority information of the QoS controlinformation. For example, the SMF network element preferably selects QoScontrol information with a highest priority to determine the first QoStarget. The priority information of the QoS control information may be apriority of a QoS policy rule. The PCF network element defines apriority for each QoS policy rule. A priority of QoS control informationcorresponding to a QoS policy rule with a higher priority is alsohigher. If the QoS policy rule includes two pieces of QoS controlinformation, the PCF network element may further determine a priorityfor each piece of QoS control information included in the QoS policyrule.

The QoS control information includes one or more QoS parameters such asa 5QI, an ARP, a GBR, an MBR, and notification control. The QoS controlinformation may further include one or more QoS attribute values such asa priority, a time window value, and a maximum data burst size.

For example, if the QoS policy information includes at least priorityinformation of first QoS control information and priority information ofsecond QoS control information, the SMF network element determines asecond QoS target of the QoS flow based on the priority information ofthe first QoS control information and the priority information of thesecond QoS control information that are included in the QoS policyinformation. For example, the SMF network element selects QoS controlinformation with a higher priority from the first QoS controlinformation and the second QoS control information, and determines thesecond QoS target based on the QoS control information with the higherpriority. The SMF network element determines the second QoS target basedon the priority information of the first QoS control information and thepriority information of the second QoS control information, so that anoptimal QoS target can be selected for the QoS flow, to ensure QoS ofthe QoS flow.

Optionally, the QoS control information includes GBR information. Whenthe QoS policy information does not include the priority information ofthe QoS control information, the SMF network element may determine thesecond QoS target based on the GBR information of the QoS controlinformation. For example, the SMF network element preferably selects QoScontrol information with a larger GBR requirement to determine thesecond QoS target.

Step S102: The SMF network element does not process the QoS flow if theSMF network element receives, in a first preset time, second indicationinformation sent by the access network apparatus, where the secondindication information is used to indicate that the first QoS target canbe met; or the SMF network element deletes or modifies the QoS flow ifthe SMF network element does not receive, in a first preset time, secondindication information sent by the access network apparatus.

Optionally, before step S102, the SMF network element determines whetherthe second indication information sent by the access network apparatusis received in the first preset time. In this embodiment, the firstpreset time may be implemented by using a timer, and a timing time ofthe timer is equal to the first preset time. The SMF network elementstarts the timer after receiving the first indication information.Before the timer expires, if the SMF network element receives the secondindication information sent by the access network apparatus, the SMFnetwork element does not process the QoS flow. Before the timer expires,if the SMF network element does not receive the second indicationinformation sent by the access network apparatus, the SMF networkelement deletes or modifies the QoS flow.

After sending the first indication information, the access networkapparatus detects, in a second preset time, whether the first QoS targetcan be met. If the first QoS target can be met in the second presettime, the access network apparatus sends the second indicationinformation to the SMF network element. If the first QoS target cannotbe met in the second preset time, optionally, the access networkapparatus may send third indication information to the SMF networkelement, where the third indication information is used to indicate thatthe first QoS target cannot be met; or the access network apparatus doesnot send any message to the SMF network element.

Optionally, the SMF network element deletes or modifies the QoS flow ifthe SMF network element receives, in the first preset time, thirdindication information sent by the access network apparatus, where thethird indication information is used to indicate that the first QoStarget cannot be met. The SMF network element determines, based on thethird indication information, that a network resource of the accessnetwork apparatus is still short. To ensure quality of service of aservice, the SMF network element determines to delete or modify the QoSflow.

In this embodiment, if the SMF network element receives, in the firstpreset time, the second indication information sent by the accessnetwork apparatus, the SMF network element determines, based on thesecond indication information, that the first QoS target of the QoS flowcan be met. It indicates that a resource shortage of the access networkapparatus is merely temporary, and the SMF network element does notprocess the QoS flow. That the SMF network element does not process theQoS flow herein means that the SMF network element does not delete ormodify the QoS flow, but it is not ensured that the SMF network elementdoes not perform a possible processing operation in another normalprogram.

In this embodiment, if the SMF network element does not receive, in thefirst preset time, the second indication information sent by the accessnetwork apparatus, the SMF network element determines that the firsttarget of the QoS flow cannot be met, and the SMF network elementdeletes or modifies the QoS flow. Optionally, the SMF network elementmay determine, based on a policy configured by the PCF network element,to delete or modify the QoS flow. For example, the policy is defined asfollows: When receiving the second indication information, the SMFnetwork element reports the second indication information to the PCFnetwork element. In this case, when the PCF network element determinesto delete all affected QoS policy rules, the SMF network element deletesthe QoS flow. The affected rule is a QoS policy rule in which the firstQoS target cannot be met. Alternatively, the policy is defined asfollows: When the PCF network element determines to modify some or allQoS policy rules, the SMF network element modifies a corresponding QoSflow according to a modified rule.

In this embodiment, modifying the QoS flow is modifying the first QoStarget of the QoS flow to the second QoS target. An existing deletionprocedure may be used for a QoS flow deletion procedure, and an existingmodification procedure or a modification manner provided in Embodiment 2of this application may be used for a QoS flow modification procedure.For details, refer to the following embodiments. The details are notdescribed herein.

In the prior art, when the QoS target of the QoS flow cannot be met, theSMF network element immediately deletes or modifies the QoS flow. As aresult, a QoS flow service cannot be served or quality of service of aservice is reduced. In the method in this embodiment, when the QoStarget of the QoS flow cannot be met, the SMF network element does notimmediately delete or modify the QoS flow, but delays for the firstpreset time to detect the QoS target of the QoS flow in the first presettime. If the QoS target still cannot be reached in the first presettime, the SMF network element deletes or modifies the QoS flow, to avoida problem that a QoS flow service cannot be served or quality of serviceof a service is reduced because the SMF network element immediatelydeletes or modifies the QoS flow when resources of the access networkapparatus are temporarily short. The first preset time may be determinedby the SMF network element according to a local policy, or may beobtained from the PCF network element. Alternatively, the first presettime is provided by another network element having a function ofproviding a preset time, for example, a big data analysis function.

Optionally, after receiving the first indication information, the SMFnetwork element determines, based on the first indication information,an operation to be performed on the QoS flow. The operation is thedeleting or modifying the QoS flow, and a state of the operation is ato-be-performed state. In this embodiment, after determining theoperation to be performed on the QoS flow, the SMF network element doesnot immediately perform the operation, but marks the state of theoperation as the to-be-performed state. The SMF network element deletesstate information of the operation if the SMF network element receives,in the first preset time, the second indication information sent by theaccess network apparatus; or the SMF network element deletes or modifiesthe QoS flow if the SMF network element does not receive, in the firstpreset time, the second indication information sent by the accessnetwork apparatus.

That the SMF network element determines to perform the modificationoperation on the QoS flow includes: The SMF network element determinesthe second QoS target of the QoS flow. Because determining the operationto be performed on the QoS flow and detecting whether the secondindication information is received may be performed concurrently, themethod in this application can shorten a time of a QoS flow modificationprocedure and reduce impact on a service compared with determining,after the first preset time, to perform the modification operation onthe QoS flow.

It should be noted that the indication information (including the firstindication information, the second indication information, the thirdindication information, and the like) in this embodiment and thefollowing embodiments is a capability used to indicate whether theapparatus can meet the QoS target, or the indication information is usedto indicate a state that has been met by the apparatus.

In this embodiment, the SMF network element receives the firstindication information sent by the access network apparatus, where thefirst indication information is used to indicate that the first QoStarget of the QoS flow cannot be met; and then the SMF network elementdetermines whether the SMF network element receives, in the first presettime, the second indication information sent by the access networkapparatus, where the second indication information is used to indicatethat the first QoS target can be met. If the SMF network elementreceives the second indication information, the SMF network element doesnot process the QoS flow. If the SMF network element does not receivethe second indication information, the SMF network element deletes ormodifies the QoS flow. In the method, when the QoS target of the QoSflow cannot be met, the SMF network element does not immediately deleteor modify the QoS flow. Instead, the SMF network element deletes ormodifies the QoS flow only when the QoS target of the QoS flow stillcannot be met within a delay of the first preset time, to avoid aproblem that a QoS flow service cannot be served or quality of serviceof a service is reduced because the SMF network element immediatelydeletes or modifies the QoS flow when resources of the access networkapparatus are temporarily short.

FIG. 9 is a flowchart of a QoS flow control method according toEmbodiment 2 of the present invention. It should be noted that themethods in Embodiment 1 and Embodiment 2 may be independently used, ormay be used in combination. When the method in Embodiment 1 isindependently used, after determining to modify the QoS flow, the SMFnetwork element modifies the QoS flow in an existing modificationprocedure. When Embodiment 1 and Embodiment 2 are combined, afterdetermining to modify the QoS flow, the SMF network element modifies theQoS flow in the method in Embodiment 2. As shown in FIG. 9 , the methodprovided in this embodiment includes the following steps.

Step S201: An SMF network element receives first indication informationsent by an access network apparatus, where the first indicationinformation is used to indicate that a first QoS target of a QoS flowcannot be met, the first QoS target includes a first GFBR, and the QoSflow is a flow on which same QoS processing is performed.

Step S202: The SMF network element determines a second QoS target of theQoS flow based on QoS policy information, where the second QoS targetincludes a second GFBR, and the QoS policy information includes at leastfirst QoS control information and second QoS control information.

In this embodiment, after receiving the first indication information,the SMF network element determines the second QoS target of the QoS flowbased on the QoS policy information. Before determining the second QoStarget of the QoS flow, the SMF network element needs to obtain the QoSpolicy information. In this embodiment, because the at least two piecesof QoS control information included in the QoS policy information canmeet a QoS requirement of the QoS flow, the second QoS target determinedbased on the QoS control information can meet the QoS requirement of theQoS flow. Different from the prior art, in the solution in thisembodiment, a QoS target of the QoS flow is modified from the first QoStarget to the second QoS target, and QoS quality of the QoS flow is notreduced.

The SMF network element may obtain the QoS policy information in thefollowing manners: In a manner, the QoS policy information ispreconfigured on the SMF network element; in another manner, the SMFnetwork element receives QoS policy information sent by the PCF networkelement; and in still another manner, the QoS policy informationincludes QoS policy information locally configured by the SMF networkelement and QoS policy information configured by the PCF networkelement. Optionally, the QoS policy information sent by the PCF networkelement is generated by the PCF network element based on one or at leasttwo QoS requirements sent by an AF network element.

In this embodiment, the SMF network element may determine the second QoStarget of the QoS flow in the following manners.

In a first manner, if the QoS policy information further includespriority information of each of at least two pieces of QoS controlinformation, the SMF network element determines the second QoS target ofthe QoS flow based on the priority information that is of each piece ofQoS control information and that is included in the QoS policyinformation.

For example, if the QoS policy information includes QoS controlinformation whose priority is the same as that of QoS controlinformation corresponding to the first QoS target, the SMF networkelement determines the second QoS target based on the QoS controlinformation whose priority is the same as that of the QoS controlinformation corresponding to the first QoS target. If the QoS policyinformation does not include QoS control information whose priority isthe same as that of QoS control information corresponding to the firstQoS target, the SMF network element selects QoS control information witha secondary priority in the QoS control information corresponding to thefirst QoS target, and determines the second QoS target based on the QoScontrol information with the secondary priority.

In a second manner, the SMF network element determines the second QoStarget of the QoS flow based on GBR information of the first QoS controlinformation and GBR information of the second QoS control informationthat are included in the QoS policy information.

When the QoS policy information includes GBR information of each pieceof QoS control information, an AMF network element determines the secondQoS target of the QoS flow based on the GBR information of the QoScontrol information. For example, the SMF network element selects QoScontrol information with a maximum GBR from remaining QoS controlinformation, and determines the second QoS target based on the QoScontrol information with the maximum GBR.

In a third manner, the SMF network element determines at least one thirdQoS target based on at least two pieces of QoS control informationincluded in the QoS policy information, and then sends the third QoStarget to the access network apparatus. The SMF network element receivesa fourth QoS target sent by the access network apparatus, where thefourth QoS target is determined by the access network apparatus based onthe third QoS target, and the fourth QoS target is a QoS target that canbe met by the access network apparatus. Finally, the SMF network elementdetermines the second QoS target based on the fourth QoS target.

In the first two manners, the SMF network element determines the secondQoS target of the QoS flow in a manner of the SMF network element. Inthe third manner, the SMF network element and the access networkapparatus determine the second QoS target through negotiation, so thatit can be ensured that the second QoS target determined for the QoS flowmatches a resource of the access network apparatus, and the resource ofthe access network apparatus can be used to a maximum extent.

When determining the third QoS target based on the at least two piecesof QoS control information, the SMF network element may alternativelydetermine the third QoS target based on priority information or abandwidth requirement of the QoS control information. For details, referto the foregoing descriptions. Details are not described herein again. Aquantity of third QoS targets may be preconfigured. The SMF networkelement may select some QoS control information from the QoS policyinformation to determine the third QoS target, or may select all QoScontrol information to determine the third QoS target. One third QoStarget is generated for each piece of QoS control information. Forexample, the SMF network element selects one piece of QoS controlinformation with a highest priority to determine one third QoS target,or the SMF network element selects two pieces of QoS control informationwith a higher priority to respectively determine one third QoS target.

After receiving the third QoS target, the access network apparatusdetermines a fourth QoS target based on the third QoS target, where thefourth QoS target is a QoS target that can be met by the access networkapparatus. For example, the access network apparatus determines thefourth QoS target based on an available resource of the access networkapparatus and the third QoS target. Optionally, the access networkapparatus selects, from the third QoS target, a QoS target that can bemet by the access network apparatus as the fourth QoS target. If none ofQoS targets in the third QoS target can be met by the access networkapparatus, the access network apparatus can return a QoS target that canbe met by the access network apparatus other than the third QoS target.Optionally, the fourth QoS target is a maximum QoS target that can bemet by the access network apparatus.

When determining the second QoS target based on the fourth QoS target,the SMF network element may directly use the fourth QoS target as thesecond QoS target, or may process the fourth QoS target to obtain thesecond QoS target. For example, a GFBR included in the fourth QoS targetfluctuates in a specific range and then is used as the second QoStarget.

In a fourth manner, the SMF network element sends at least two QoStargets of the QoS flow to the access network apparatus, and the SMFnetwork element may send the at least two QoS targets of the QoS flow tothe access network apparatus in a QoS flow establishment or modificationprocess. The SMF network element receives a fifth QoS target sent by theaccess network apparatus, where the fifth QoS target is a QoS targetthat can be met by the access network apparatus, and the fifth QoStarget is determined by the access network apparatus based on the atleast two QoS targets when the first QoS target of the QoS flow cannotbe met. Correspondingly, the SMF network element determines the secondQoS target based on the fifth QoS target.

In this manner, the SMF network element and the access network apparatusdetermine the second QoS target through negotiation. A difference fromthe third manner in which the SMF network element triggers the accessnetwork apparatus to send the QoS target that can be met by the accessnetwork apparatus lies in that in the fourth manner, when the first QoStarget cannot be met, the access network apparatus actively reports theQoS target that can be met by the access network apparatus, so that theSMF network element determines the second QoS target based on the QoStarget that can be met by the access network apparatus. Therefore, itcan be ensured that the second QoS target determined for the QoS flowmatches a resource of the access network apparatus, and the resource ofthe access network apparatus can be used to a maximum extent.

Optionally, when determining the fifth QoS target, the access networkapparatus determines the fifth QoS target based on an available resourceand the at least two QoS targets sent by the SMF network element.Optionally, the access network apparatus may select one QoS target fromthe at least two QoS targets as the fifth QoS target based on theavailable resource. For example, the access network apparatus selects aQoS target closest to the available resource from the at least two QoStargets as the fifth QoS target.

Step S203: The SMF network element sends the second QoS target to theaccess network apparatus.

The SMF network element may actively send the second QoS target to theaccess network apparatus, to trigger modification of the QoS flow.Alternatively, the SMF network element may send the second QoS target tothe access network apparatus when receiving a QoS flow modificationnotification indication sent by the access network apparatus.

Optionally, the SMF network element starts a timer after receiving thefirst indication information, and deletes the timer after sending thesecond QoS target to the access network apparatus. Certainly, a deletiontime of the timer is not limited to a time after the second QoS targetis sent. The SMF network element may delete the timer at any time afterthe timer is started.

In this embodiment, the SMF network element receives the firstindication information sent by the access network apparatus, where thefirst indication information is used to indicate that the first QoStarget of the QoS flow cannot be met. In this case, the SMF networkelement determines the second QoS target of the QoS flow based on theQoS policy information, where the QoS policy information includes the atleast two pieces of QoS control information, and the SMF network elementsends the second QoS target to the access network apparatus. Because theat least two pieces of QoS control information included in the QoSpolicy information can meet a QoS requirement of the QoS flow, thesecond QoS target determined based on the QoS control information canalso meet the QoS requirement of the QoS flow. Different from the priorart, in the solution in this embodiment, a QoS target of the QoS flow ismodified from the first QoS target to the second QoS target, and QoSquality of the QoS flow is not reduced.

FIG. 10 is a flowchart of a QoS flow control method according toEmbodiment 3 of this application. The QoS flow control method isdescribed in this embodiment from a perspective of an access networkapparatus. As shown in FIG. 10 , the method in this embodiment mayinclude the following steps.

Step S301: The access network apparatus sends first indicationinformation to an SMF network element, where the first indicationinformation is used to indicate that a first QoS target of a QoS flow ofUE cannot be met, the first QoS target includes a first GFBR, and thefirst QoS flow is a flow on which same QoS processing is performed.

During running of the QoS flow, the access network apparatus detectswhether the first QoS target of the QoS flow can be met. In a manner,when the access network apparatus detects that the first QoS targetcannot be met, optionally, a profile of the QoS flow includesnotification control, and the access network apparatus sends the firstindication information to the SMF network element. In another manner,when the access network apparatus detects that the first QoS targetcannot be met, the access network apparatus sends the first indicationinformation to the SMF network element regardless of whether a profileof the QoS flow includes notification control.

Step S302: If the first QoS target can be met in a second preset time,the access network apparatus sends second indication information to theSMF network element, where the second indication information is used toindicate that the first QoS target can be met.

Optionally, if the first QoS target cannot be met in the second presettime, the access network apparatus sends third indication information tothe SMF network element, where the third indication information is usedto indicate that the first QoS target cannot be met.

In this embodiment, when determining whether the first QoS target can bemet, the access network apparatus determines, based on a state of thefirst QoS target in the second preset time, namely, a state of the QoSflow in an entire second preset time, whether the first QoS target ismet. In addition, the access network apparatus may determine, when orafter the second preset time ends, whether the first QoS target is met.

The second preset time may be implemented by using a timer. The accessnetwork apparatus starts the timer after sending the first indicationinformation. A timing time of the timer is equal to the second presettime. Before the timer expires, the access network apparatus detectswhether the first QoS target can be met. Before the timer expires, ifthe first QoS target can be met, the access network apparatus sends thesecond indication information to the SMF network element. When the timerexpires, if the first QoS target cannot be met, the access networkapparatus sends the third indication information to the SMF networkelement.

Optionally, a timer calculates the second preset time; and the accessnetwork apparatus deletes the timer if the access network apparatusreceives, in the second preset time, a deletion or modification requestthat is for the QoS flow and that is sent by the SMF network element.After deleting the timer, correspondingly, the access network apparatusdeletes information about the QoS flow, initiates an RRC modificationprocedure to the UE, and deletes a binding relationship between the QoSflow and a DRB, or deletes a corresponding DRB, or modifies acorresponding DRB.

Optionally, if the access network apparatus does not receive amodification procedure or deletion procedure that is for the QoS flowand that is sent by the SMF network element, the access networkapparatus sends a deletion request for the QoS flow to the SMF networkelement. Optionally, after sending the third indication information, ifthe access network apparatus does not receive, in a third preset time,the modification procedure or deletion procedure that is for the QoSflow and that is sent by the SMF network element, the access networkdevice may send the deletion request for the QoS flow to the SMF networkelement, to trigger the deletion procedure for the QoS flow. The thirdpreset time may be implemented by using a timer. The access networkapparatus starts the timer after sending the third indicationinformation. Before the timer expires, if the access network apparatusdoes not receive the modification procedure or deletion procedure thatis for the QoS flow and that is sent by the SMF network element, theaccess network device may send the deletion request for the QoS flow tothe SMF network element, where the deletion request for the QoS flow isused to instruct to delete the QoS flow.

Optionally, after sending the third indication message, the accessnetwork apparatus receives a deletion request sent by the SMF networkelement, where the deletion request is used to delete the QoS flow.

In this embodiment, the access network apparatus sends the firstindication information to the SMF network element, where the firstindication information is used to indicate that the first QoS target ofthe QoS flow of the UE cannot be met. If the first QoS target can be metin the second preset time, the access network apparatus sends the secondindication information to the SMF network element, where the secondindication information is used to indicate that the first QoS target canbe met. If the first QoS target cannot be met in the second preset time,the access network apparatus sends the third indication information tothe SMF network element, where the third indication information is usedto indicate that the first QoS target cannot be met. In the method, whenthe first QoS target cannot be met, after sending the first indicationinformation, the access network apparatus detects, in the second presettime, whether the first QoS target can be met, and notifies the SMFnetwork element, so that when a QoS target of the QoS flow cannot bemet, the SMF network element does not immediately delete or modify theQoS flow. Instead, the SMF network element deletes or modifies the QoSflow only when the QoS target of the QoS flow still cannot be met withina delay of the first preset time, to avoid a problem that a QoS flowservice cannot be served or quality of service of a service is reducedbecause the SMF network element immediately deletes or modifies the QoSflow when resources of the access network apparatus are temporarilyshort.

FIG. 11 is a flowchart of a QoS flow control method according toEmbodiment 4 of this application. As shown in FIG. 11 , according toEmbodiment 3, the method in this embodiment may further include thefollowing steps.

Step S401: An access network apparatus sends first indicationinformation to an SMF network element, where the first indicationinformation is used to indicate that a first QoS target of a QoS flow ofUE cannot be met, and the first QoS target includes a first GFBR.

Step S402: If the first QoS target cannot be met in a second presettime, the access network apparatus sends third indication information tothe SMF network element, where the third indication information is usedto indicate that the first QoS target cannot be met.

Step S403: The access network apparatus receives a second QoS targetsent by the SMF network element, where the second QoS target includes asecond GFBR.

After the access network apparatus sends the first indicationinformation, if the SMF network element determines, based on the firstindication information, to modify the QoS flow, the SMF network elementsends the second QoS target to the access network apparatus.

Step S404: The access network apparatus modifies the QoS flow based onthe second QoS target.

The access network apparatus modifies a target of the QoS flow from thefirst QoS target to the second QoS target based on the second QoStarget.

Optionally, before receiving the second QoS target sent by the SMFnetwork element, the access network apparatus receives at least onethird QoS target sent by the SMF network element, and the access networkapparatus determines a fourth QoS target based on the third QoS target.Optionally, the access network apparatus selects one QoS target from thethird QoS target as the fourth QoS target, where the fourth QoS targetis a QoS target that can be met by the access network apparatus, and theaccess network apparatus sends the fourth QoS target to the SMF networkelement. The access network apparatus sends the fourth QoS target to theSMF network element, so that the SMF network element determines thesecond QoS target based on the fourth QoS target, the determined secondQoS target matches a resource of the access network apparatus, and theresource of the access network apparatus is used to a maximum extent.

Optionally, before sending the first indication information to the SMFnetwork element, the access network apparatus receives at least two QoStargets of the QoS flow that are sent by the SMF network element. The atleast two QoS targets may be sent by the SMF network element to theaccess network apparatus when the QoS flow is established. When thefirst QoS target of the QoS flow cannot be met, the access networkapparatus selects a fifth QoS target from the at least two QoS targets,where the fifth QoS target is a QoS target that can be met by the accessnetwork apparatus. The access network apparatus sends the fifth QoStarget to the SMF network element, so that the SMF network elementdetermines the second QoS target based on the fifth QoS target, thedetermined second QoS target matches a resource of the access networkapparatus, and the resource of the access network apparatus is used to amaximum extent.

In this embodiment, the access network apparatus sends the firstindication information to the SMF network element, where the firstindication information is used to indicate that the first QoS target ofthe QoS flow of the UE cannot be met. If the first QoS target cannot bemet in the second preset time, the access network apparatus sends thethird indication information to the SMF network element, where the thirdindication information is used to indicate that the first QoS targetcannot be met, and the access network apparatus receives the second QoStarget sent by the SMF network element, and modifies the QoS flow basedon the second QoS target. QoS of a service is ensured because the secondQoS target determined by the SMF network element can meet a requirementof the QoS flow.

FIG. 12 is a signaling flowchart of a QoS flow control method accordingto Embodiment 5 of this application. As shown in FIG. 12 , the methodprovided in this embodiment includes the following steps.

Step S501: UE establishes a PDU session (session) with a network.

For a session establishment process, refer to an existing establishmentprocedure. Details are not described herein. Optionally, in the sessionestablishment process, an SMF network element sends a value of a timerto an access network apparatus.

Step S502: When an AF network element determines to establish a servicefor the UE, the AF network element sends service information and atleast two GBR QoS requirements to a PCF network element.

The AF network element may add the service information and the at leasttwo GBR QoS requirements to an NPCF networkelement_PolicyAuthorization_create_service service procedure, and sendthe service procedure to the PCF network element. The GBR QoSrequirement includes a notification control indication. Optionally, theservice procedure further includes priority information of two GBR QoSrequirements.

Step S503: The PCF network element sends at least two pieces of GBR QoScontrol information to the SMF network element.

The PCF network element may add the at least two pieces of GBR QoScontrol information to an Npcf_SMPolicyControl_UpdateNotify service, andsend the service to the SMF network element. The service is sent by thePCF network element based on a service request of the AF networkelement, and the GBR QoS control information is generated by the PCFnetwork element based on the GBR QoS requirement sent by the AF networkelement. Optionally, the service further includes priority informationof the GBR QoS control information.

Step S504: The SMF network element establishes a corresponding QoS flowbased on a message sent by the PCF network element.

The SMF network element may establish the corresponding QoS flow basedon the service message sent by the PCF network element. In anestablishment process, the SMF network element activates or establishesthe corresponding QoS flow based on the priority information of the GBRQoS control information. To be specific, the SMF network element firstuses GBR QoS control information with a highest priority to establishthe QoS flow, where a QoS target corresponding to the GBR QoS controlinformation with the highest priority is a first QoS target. When theSMF network element does not obtain the priority information of the GBRQoS control information, the SMF network element determines, based on abandwidth requirement priority or guaranteed bit rate GBR information ofthe GBR QoS control information, to preferably use QoS controlinformation with a higher bandwidth requirement or a higher guaranteedbit rate GBR to establish the QoS flow, where a QoS target correspondingto the QoS control information with the higher bandwidth requirement isa first QoS target.

Step S505: The UE establishes a QoS flow based on notification controlwith the network.

Step S506: The access network apparatus starts the timer when the accessnetwork apparatus detects that the first QoS target of the QoS flowcannot be met.

When detecting that the first QoS target cannot be met, the accessnetwork apparatus reads a profile of the QoS flow. When the profile ofthe QoS flow includes notification control, the access network apparatusstarts the timer.

Step S507: The access network apparatus sends first indicationinformation to an AMF network element.

The first indication information is used to indicate that the first QoStarget cannot be met. The access network apparatus may add the firstindication information to an N2 message, and send the N2 message to theAMF network element. The N2 message includes a PDU session ID and N2 SMinformation. The N2 SM information includes a QoS flow identifier (QFI)and the first indication information, and the first indicationinformation is used to indicate that the first QoS target of the QoSflow cannot be met.

Step S508: The AMF network element sends the first indicationinformation to the SMF network element.

The AMF network element may add the first indication information to anNsmf_PDUSessionUpdateSMContext message, and send the message to the SMFnetwork element. The message includes a QFI and the first indicationinformation.

Step S509: The SMF network element determines, based on the at least twopieces of GBR QoS control information sent by the PCF network element,to modify the QoS flow.

In this embodiment, the SMF network element may determine a second QoStarget of the QoS flow based on priority information or a bandwidthrequirement of the GBR QoS control information.

Step S510: Perform a modification procedure for the QoS flow.

Optionally, the modification procedure for the QoS flow may include thefollowing steps (not shown in the figure).

S5101: The SMF network element sends the second QoS target to the AMFnetwork element.

The SMF network element may add the second QoS target to anNamf_Communication_N1N2MessageTransfer message, and send the message tothe AMF network element. The message includes N2 SM information and anN1 SM container. The N2 SM information includes a PDU session ID, a QFI,and a QoS profile (including the second QoS target). The N1 SM containerincludes a PDU session ID, a QoS rule (including the first QoS target)that cannot be met, and an operation (for example, deletion ormodification) of the QoS rule.

S5102: The AMF network element sends the second QoS target to the accessnetwork apparatus.

The AMF network element may add the second QoS target to an N2 PDUsession request, and send the N2 PDU session request to the accessnetwork apparatus. The request includes N2 SM information received fromthe SMF network element and a NAS message. The NAS message includes aPDU session ID and an N1 SM container. The access network apparatusdeletes the started timer after receiving the second QoS target.

S5103: The access network apparatus performs a specific signalingprocedure with the UE.

The access network apparatus performs the specific signaling procedurewith the UE based on information sent by the SMF network element. Forexample, when the UE accesses a 3GPP RAN, an RRC connectionreconfiguration is performed between the UE and the access networkapparatus to modify a corresponding RAN resource.

S5104: The access network apparatus interacts with a core network deviceto modify the QoS flow.

S5105: The access network apparatus sends an N2 session response to theAMF network element.

The N session response message includes N2 SM information.

S5106: The AMF network element uses an Nsmf_PDUSession_UpdateSMContextservice operation, where the service includes N2 SM information. The SMFnetwork element sends an Nsmf_PDUSession_UpdateSMContext response to theAMF network element.

S5107: The UE sends a NAS message to respond to a PDU sessionmodification command, where the NAS message includes a PDU session IDand an N1 SM container, and the N1 SM container is determined by the PDUsession modification command.

S5108: The access network apparatus forwards the NAS message to the AMFnetwork element.

S5109: The AMF network element forwards the N1 SM container to the SMFnetwork element by using Nsmf_PDUSession_UpdateSMContext. The SMFnetwork element sends the Nsmf_PDUSession_UpdateSMContext response tothe AMF network element.

S5110: The SMF network element performs a PDU session modificationprocedure with a UPF.

S5111: The SMF network element sends Nsmf_EventExposure_Notify to thePCF network element, where Nsmf_EventExposure_Notify includes anaffected PCC rule. The PCF network element sends a response message tothe SMF network element.

S5112: The PCF network element sends Npcf_EventExposure_Notify to the AFnetwork element, where Npcf_EventExposure_Notify includes a QoSrequirement of a performed service. The AF network element sends aresponse message to the PCF network element.

In this embodiment, a QoS flow control process is described by using anexample in which communication is performed in a network architecturethrough a service-based interface. Certainly, communication mayalternatively be not performed through a service-based interface.Correspondingly, messages exchanged between the network elements aredifferent. However, content for QoS control carried in the messages isthe same.

FIG. 13A and FIG. 13B are a signaling flowchart of a QoS flow controlmethod according to Embodiment 6 of this application. As shown in FIG.13A and FIG. 13B, the method provided in this embodiment includes thefollowing steps.

Step S601: UE establishes a PDU session with a network.

For a session establishment process, refer to an existing establishmentprocedure. Details are not described herein. Optionally, in the sessionestablishment process, an SMF network element sends a value of a timerto an access network apparatus.

Step S602: When an AF network element determines to establish a servicefor the UE, the AF network element sends service information and atleast two GBR QoS requirements to a PCF network element.

The AF network element may add the service information and the at leasttwo GBR QoS requirements to an Npcf_PolicyAuthorization_create_serviceservice procedure, and send the service procedure to the PCF networkelement. The GBR QoS requirement includes a notification controlindication. Optionally, the service procedure further includes priorityinformation of two GBR QoS requirements.

Step S603: The PCF network element sends at least two pieces of GBR QoScontrol information to the SMF network element.

The PCF network element may add the at least two pieces of GBR QoScontrol information to an Npcf_SMPolicyControl_UpdateNotify service, andsend the service to the SMF network element. The service is sent by thePCF network element based on a service request of the AF networkelement, and the GBR QoS control information is generated by the PCFnetwork element based on the GBR QoS requirement sent by the AF networkelement. Optionally, the service further includes priority informationof the GBR QoS control information.

Step S604: The SMF network element establishes a corresponding QoS flowbased on a message sent by the PCF network element.

The SMF network element may establish the corresponding QoS flow basedon the service message sent by the PCF network element. In anestablishment process, the SMF network element activates thecorresponding QoS flow based on the priority information of the GBR QoScontrol information. To be specific, the SMF network element first usesGBR QoS control information with a highest priority to establish the QoSflow, where a QoS target corresponding to the GBR QoS controlinformation with the highest priority is a first QoS target. When theSMF network element does not obtain the priority information of the GBRQoS control information, the SMF network element determines, based on abandwidth requirement priority or guaranteed bit rate information of theGBR QoS control information, to preferably use QoS control informationwith a higher bandwidth requirement or a higher guaranteed bit rate toestablish the QoS flow, where a QoS target corresponding to the QoScontrol information with the higher bandwidth requirement is a first QoStarget.

Step S605: The UE establishes a QoS flow based on notification controlwith the network.

Step S606: The access network apparatus starts the timer when the accessnetwork apparatus detects that the first QoS target of the QoS flowcannot be met.

When detecting that the first QoS target cannot be met, the accessnetwork apparatus reads a profile of the QoS flow. When the profile ofthe QoS flow includes notification control, the access network apparatusstarts the timer.

Step S607: The access network apparatus sends first indicationinformation to an AMF network element.

The access network apparatus may add the first indication information toan N2 message, and send the N2 message to the AMF network element. TheN2 message includes a PDU session ID and N2 SM information. The N2 SMinformation includes a QoS flow identifier (QFI) and the firstindication information, and the first indication information is used toindicate that the first QoS target of the QoS flow cannot be met.

Step S608: The AMF network element sends the first indicationinformation to the SMF network element.

The AMF network element may add the first indication information to anNsmf_PDUSessionUpdateSMContext message, and send the message to the SMFnetwork element. The message includes a QFI and the first indicationinformation.

Step S609: The SMF network element determines at least one third QoStarget of the QoS flow based on the at least two pieces of GBR QoScontrol information sent by the PCF network element.

Specifically, for a specific manner of determining the third QoS targetby the SMF network element, refer to the related descriptions inEmbodiment 2. Details are not described herein again.

Step S610: The SMF network element sends the third QoS target to the AMFnetwork element.

The SMF network element may add the third QoS target to anNamf_Communication_N1N2MessageTransfer message, and send the message tothe AMF network element. The message includes N2 SM information and anN1 SM container. The N2 SM information includes a PDU session ID, a QFI,and a QoS profile (including the third QoS target). The N1 SM containerincludes a PDU session ID, a QoS rule (including the first QoS target)that cannot be met, and an operation (for example, deletion ormodification) of the QoS rule.

Step S611: The AMF network element sends the third QoS target to theaccess network apparatus.

The AMF network element may add the third QoS target to an N2 PDUsession request, and send the N2 PDU session request to the accessnetwork apparatus. The session request includes N2 SM informationreceived from the SMF network element and a NAS message. The NAS messageincludes a PDU session ID and an N1 SM container.

Step S612: The access network apparatus deletes the started timer, anddetermines fourth QoS based on the third QoS.

After receiving the third QoS target, the access network apparatusdeletes the started timer, and determines the fourth QoS target based onthe received third QoS target and an available resource, where thefourth QoS target is a QoS target that can be reached by the accessnetwork apparatus.

Step S613: The access network apparatus sends the fourth QoS target tothe AMF network element.

The access network apparatus may add the fourth QoS target to an N2session response, and send the N2 session response to the AMF networkelement. The session response message includes N2 SM information, the N2SM information includes the fourth QoS target supported by an (R)AN, andthe fourth QoS target includes a fourth GFBR. Optionally, the fourth QoStarget further includes a fourth MFBR.

Step S614: The AMF network element sends the fourth QoS target to theSMF network element.

The AMF network element may add the fourth QoS target to anNsmf_PDUSession_UpdateSMContext service operation, and send the serviceoperation to the SMF network element. The service includes N2 SMinformation. The SMF network element sends anNsmf_PDUSession_UpdateSMContext response to the AMF network element.

Step S615: The SMF network element determines a second QoS target basedon the fourth QoS target.

Step S616: Perform a modification procedure for the QoS flow.

Optionally, the modification procedure for the QoS flow may include thefollowing steps (not shown in the figure).

S6161: The SMF network element sends the second QoS target to the AMFnetwork element.

The SMF network element may add the second QoS target to anNamf_Communication_N1N2MessageTransfer message, and send the message tothe AMF network element. The message includes N2 SM information and anN1 SM container. The N2 SM information includes a PDU session ID, a QFI,and a QoS profile (including the second QoS target). The N1 SM containerincludes a PDU session ID, a QoS rule (including the first QoS target)that cannot be met, and an operation (for example, deletion ormodification) of the QoS rule.

S6162: The AMF network element sends the second QoS target to the accessnetwork apparatus.

The AMF network element may add the second QoS target to an N2 PDUsession request, and send the N2 PDU session request to the accessnetwork apparatus. The request includes N2 SM information received fromthe SMF network element and a NAS message. The NAS message includes aPDU session ID and an N1 SM container. The access network apparatusdeletes the started timer after receiving the second QoS target.

S6163: The access network apparatus performs a specific signalingprocedure with the UE.

The access network apparatus performs the specific signaling procedurewith the UE based on information sent by the SMF network element. Forexample, when the UE accesses a 3GPP RAN, an RRC connectionreconfiguration is performed between the UE and the access networkapparatus to modify a corresponding RAN resource.

S6164: The access network apparatus interacts with a core network deviceto modify the QoS flow.

S6165: The access network apparatus sends an N2 session response to theAMF network element.

The N session response message includes N2 SM information.

S6166: The AMF network element uses an Nsmf_PDUSession_UpdateSMContextservice operation, where the service includes N2 SM information. The SMFnetwork element sends an Nsmf_PDUSession_UpdateSMContext response to theAMF network element.

S6167: The UE sends a NAS message to respond to a PDU sessionmodification command, where the NAS message includes a PDU session IDand an N1 SM container, and the N1 SM container is determined by the PDUsession modification command.

S6169: The access network apparatus forwards the NAS message to the AMFnetwork element.

S6195: The AMF network element forwards the N1 SM container to the SMFnetwork element by using Nsmf_PDUSession_UpdateSMContext. The SMFnetwork element sends the Nsmf_PDUSession_UpdateSMContext response tothe AMF network element.

S6169: The SMF network element performs a PDU session modificationprocedure with a UPF.

S6170: The SMF network element sends Nsmf_EventExposure_Notify to thePCF network element, where Nsmf_EventExposure_Notify includes anaffected PCC rule. The PCF network element sends a response message tothe SMF network element.

S6171: The PCF network element sends Npcf_EventExposure_Notify to the AFnetwork element, where Npcf_EventExposure_Notify includes a QoSrequirement of a performed service. The AF network element sends aresponse message to the PCF network element.

In this embodiment, after the access network apparatus sends the firstindication information to the SMF network element, the SMF networkelement determines and performs the modification procedure for the QoSflow. According to Embodiment 2, in another possible implementation ofthis application, after receiving the first indication information, theSMF network element determines to modify the QoS flow. However, the SMFnetwork element does not immediately perform the modification procedurefor the QoS flow, but marks a state of the modification operation as anunperformed state. When receiving second indication information, the SMFnetwork element initiates the modification procedure or a modificationnegotiation procedure for the QoS flow, where the second indicationinformation is used to indicate that the first QoS is still not met. Inthis manner, a problem that a QoS flow service cannot be served orquality of service of a service is reduced because the SMF networkelement immediately deletes or modifies the QoS flow when resources ofan access network apparatus are temporarily short can be avoided.

FIG. 14 is a signaling flowchart of a QoS flow control method accordingto Embodiment 7 of this application. As shown in FIG. 14 , the methodprovided in this embodiment includes the following steps.

Step S701: UE establishes a PDU session (session) with a network.

For a session establishment process, refer to an existing establishmentprocedure. Details are not described herein.

Step S702: When an AF network element determines to establish a servicefor the UE, the AF network element sends service information and atleast two GBR QoS requirements to a PCF network element.

The AF network element may add the service information and the at leasttwo GBR QoS requirements to an Npcf_PolicyAuthorization_create_serviceservice procedure, and send the service procedure to the PCF networkelement. The GBR QoS requirement includes a notification controlindication. Optionally, the service procedure further includes priorityinformation of two GBR QoS requirements.

Step S703: The PCF network element sends at least two pieces of GBR QoScontrol information to an SMF network element.

The PCF network element may add the at least two pieces of GBR QoScontrol information to an Npcf_SMPolicyControl_UpdateNotify service, andsend the service to the SMF network element. The service is sent by thePCF network element based on a service request of the AF networkelement, and the GBR QoS control information is generated by the PCFnetwork element based on the GBR QoS requirement sent by the AF networkelement. Optionally, the service further includes priority informationof the GBR QoS control information.

Step S704: The SMF network element establishes a corresponding QoS flowbased on a message sent by the PCF network element.

The SMF network element may establish the corresponding QoS flow basedon the service message sent by the PCF network element. In anestablishment process, the SMF network element activates thecorresponding QoS flow based on the priority information of the GBR QoScontrol information. To be specific, the SMF network element first usesGBR QoS control information with a highest priority to establish the QoSflow, where a QoS target corresponding to the GBR QoS controlinformation with the highest priority is a first QoS target. When theSMF network element does not obtain the priority information of the GBRQoS control information, the SMF network element determines, based on abandwidth requirement priority of the GBR QoS control information, topreferably use QoS control information with a higher bandwidthrequirement to establish the QoS flow, where a QoS target correspondingto the QoS control information with the higher bandwidth requirement isa first QoS target.

Step S705: The UE establishes a QoS flow based on notification controlwith the network.

In this embodiment, in a process in which the UE establishes the QoSflow with the network, the SMF network element sends at least two QoStargets to an access network apparatus.

Step S706: The access network apparatus starts a timer when the accessnetwork apparatus detects that the first QoS target of the QoS flowcannot be met.

When detecting that the first QoS target cannot be met, the accessnetwork apparatus reads a profile of the QoS flow. When the profile ofthe QoS flow includes notification control, the access network apparatusstarts the timer, and determines a fifth QoS target based on the atleast two QoS targets sent by the SMF network element, where the fifthQoS target is a QoS target that can be met by the access networkapparatus.

Step S707: The access network apparatus sends first indicationinformation and the fifth QoS target to an AMF network element.

The first indication information is used to indicate that the first QoStarget cannot be met. The access network apparatus may add the firstindication information and the fifth QoS target to an N2 message, andsend the N2 message to the AMF network element. The N2 message includesa PDU session ID and N2 SM information. The N2 SM information includes aQoS flow identifier (QFI) and the first indication information, and thefirst indication information is used to indicate that the first QoStarget of the QoS flow cannot be met.

Step S708: The AMF network element sends the first indicationinformation and the fifth QoS target to the SMF network element.

The AMF network element may add the first indication information and thefifth QoS target to an NSMF network element_PDUSessionUpdateSMContextmessage, and send the message to the SMF network element. The messageincludes a QFI and the first indication information.

Step S709: The SMF network element interacts with the PCF networkelement based on the first indication information, to notify the PCFnetwork element that the first QoS target cannot be met.

Step S710: The SMF network element determines a second QoS target basedon the fifth QoS target.

Step S711: Perform a modification procedure for the QoS flow.

Optionally, the modification procedure for the QoS flow may include thefollowing steps (not shown in the figure).

S7110: The SMF network element sends the second QoS target to the AMFnetwork element.

The SMF network element may add the second QoS target to anNamf_Communication_N1N2MessageTransfer message, and send the message tothe AMF network element. The message includes N2 SM information and anN1 SM container. The N2 SM information includes a PDU session ID, a QFI,and a QoS profile (including the second QoS target). The N1 SM containerincludes a PDU session ID, a QoS rule (including the first QoS target)that cannot be met, and an operation (for example, deletion ormodification) of the QoS rule.

S7111: The AMF network element sends the second QoS target to the accessnetwork apparatus.

The AMF network element may add the second QoS target to an N2 PDUsession request, and send the N2 PDU session request to the accessnetwork apparatus. The session request includes N2 SM informationreceived from the SMF network element and a NAS message. The NAS messageincludes a PDU session ID and an N1 SM container.

S7112: The access network apparatus performs a specific procedure withthe UE based on the second QoS target.

For example, when the UE accesses a 3GPP RAN, an RRC connectionreconfiguration is performed between the UE and the access networkapparatus to modify a corresponding RAN resource.

S7113: The access network apparatus interacts with a core network deviceto modify the QoS flow.

S7114: The access network apparatus sends an N2 session response to theAMF network element.

The N session response message includes N2 SM information.

S7115: The AMF network element uses an Nsmf_PDUSession_UpdateSMContextservice operation, where the service includes N2 SM information. The SMFnetwork element sends an Nsmf_PDUSession_UpdateSMContext response to theAMF network element.

S7116: The UE sends a NAS message to respond to a PDU sessionmodification command, where the NAS message includes a PDU session IDand an N1 SM container, and the N1 SM container is determined by the PDUsession modification command.

S7117: The access network apparatus forwards the NAS message to the AMFnetwork element.

S7118: The AMF network element forwards the N1 SM container to the SMFnetwork element by using Nsmf_PDUSession_UpdateSMContext. The SMFnetwork element sends the Nsmf_PDUSession_UpdateSMContext response tothe AMF network element.

S7119: The SMF network element performs a PDU session modificationprocedure with a UPF.

S7120: The SMF network element sends Nsmf_EventExposure_Notify to thePCF network element, where Nsmf_EventExposure_Notify includes anaffected PCC rule. The PCF network element sends a response message tothe SMF network element.

S7121: The PCF network element sends Npcf_EventExposure_Notify to the AFnetwork element, where Npcf_EventExposure_Notify includes a QoSrequirement of a performed service. The AF network element sends aresponse message to the PCF network element.

Optionally, after a period of time, when detecting that the first QoStarget can be met, the access network apparatus notifies the SMF networkelement, so that the SMF network element can reuse the first QoS targetto transmit a service.

FIG. 15 is a signaling flowchart of a QoS flow control method accordingto Embodiment 8 of this application. As shown in FIG. 15 , the methodprovided in this embodiment includes the following steps.

Step S801: UE establishes a PDU session with a network.

For a session establishment process, refer to an existing establishmentprocedure. Details are not described herein.

Step S802: The UE establishes a QoS flow based on notification controlwith the network.

In this embodiment, in a process in which the UE establishes the QoSflow with the network, an SMF network element sends at least two QoStargets to an access network apparatus.

Step S803: The access network apparatus detects that a first QoS targetof the QoS flow cannot be met, and a profile of the QoS flow includesnotification control.

Step S804: The access network apparatus sends first indicationinformation to an AMF network element.

The access network apparatus may add the first indication information toan N2 message, and send the N2 message to the AMF network element. TheN2 message includes a PDU session ID and N2 SM information. The N2 SMinformation includes a QoS flow identifier (QFI) and the firstindication information, and the first indication information is used toindicate that the first QoS target of the QoS flow cannot be met.

Step S805: The AMF network element sends the first indicationinformation to the SMF network element.

The AMF network element may add the first indication information to anNsmf_PDUSessionUpdateSMContext message, and send the message to the SMFnetwork element. The message includes a QFI and the first indicationinformation.

The AMF network element may add the first indication information to anNSMF network element_PDUSessionUpdateSMContext message, and send themessage to the SMF network element. The message includes a QFI and thefirst indication information.

Step S806: The SMF network element determines, based on the firstindication information, an operation (including modifying or deletingthe QoS flow) to be performed on the QoS flow, starts a timer, and marksa state of the operation as a to-be-performed state.

The SMF network element interacts with a PCF network element based onthe first indication information, to determine to modify thecorresponding QoS flow or delete the QoS flow. A value of the timer maybe obtained in a process in which the SMF network element interacts withthe PCF network element, or may be obtained from the PCF network elementor a UDM in a PDU session establishment process.

Step S807: The access network apparatus detects, in a second presettime, that the first QoS target of the QoS flow is met.

Step S808: The access network apparatus sends second indicationinformation to the AMF network element.

The second indication information is used to indicate that the first QoStarget is met. The access network apparatus may add the secondindication information to an N2 message, and send the N2 message to theAMF network element. The message includes a PDU session ID and N2 SMinformation. The N2 SM information includes a QFI and the secondindication information.

Step S809: The AMF network element sends the second indicationinformation to the SMF network element.

The AMF network element may add the second indication information to anNsmf_PDUSessionUpdateSMContext message, and send the message to the SMFnetwork element. The message further includes a QFI. When receiving thesecond indication message, the SMF network element deletes the timer,and notifies the PCF network element of the event (that is, the firstQoS target is reached). The SMF network element deletes stateinformation of the operation of the QoS flow.

Step S810: The SMF network element performs a modification procedure forthe QoS flow if the SMF network element does not receive the secondindication information in a first preset time.

Optionally, the modification procedure for the QoS flow includes thefollowing steps (not shown in the figure).

S8101: Send a deletion or modification request for the QoS flow to theAMF network element.

For example, the SMF network element sendsNamf_Communication_N1N2MessageTransfer to the AMF network element. Themessage includes N2 SM information and an N1 SM container. The N2 SMinformation includes a PDU session ID, a QFI, and a QoS profile(including a second QoS target). The N1 SM container includes a PDUsession ID, a QoS rule (including the first QoS target) that cannot bemet, and an operation (for example, deletion or modification) of the QoSrule.

S8102: The AMF network element sends the deletion or modificationrequest for the QoS flow to the access network apparatus.

The AMF network element may add the deletion or modification request forthe QoS flow to an N2 PDU session request, and send the N2 PDU sessionrequest to the access network apparatus. The request includes N2 SMinformation received from the SMF network element and a NAS message. TheNAS message includes a PDU session ID and an N1 SM container.

S8103: The access network apparatus performs a specific procedure withthe UE based on the second QoS target.

For example, when the UE accesses a 3GPP RAN, an RRC connectionreconfiguration is performed between the UE and the access networkapparatus to modify a corresponding RAN resource.

S8104: The access network apparatus interacts with a core network deviceto modify the QoS flow.

An existing procedure may be used for a process in which the accessnetwork apparatus interacts with the core network device. In thisembodiment, the interaction process is described by using an example inwhich communication is performed in a network architecture through aservice-based interface.

S8105: The access network apparatus sends an N2 session response to theAMF network element.

The N session response message includes N2 SM information.

S8106: The AMF network element uses an Nsmf_PDUSession_UpdateSMContextservice operation, where the service includes N2 SM information. The SMFnetwork element sends an Nsmf_PDUSession_UpdateSMContext response to theAMF network element.

S8107: The UE sends a NAS message to respond to a PDU sessionmodification command, where the NAS message includes a PDU session IDand an N1 SM container, and the N1 SM container is determined by the PDUsession modification command.

S8108: The access network apparatus forwards the NAS message to the AMFnetwork element.

S8109: The AMF network element forwards the N1 SM container to the SMFnetwork element by using Nsmf_PDUSession_UpdateSMContext. The SMFnetwork element sends the Nsmf_PDUSession_UpdateSMContext response tothe AMF network element.

S8110: The SMF network element performs a PDU session modificationprocedure with a UPF.

S8111: The SMF network element sends Nsmf_EventExposure_Notify to thePCF network element, where Nsmf_EventExposure_Notify includes anaffected PCC rule. The PCF network element sends a response message tothe SMF network element.

S8112: The PCF network element sends Npcf_EventExposure_Notify to an AFnetwork element, where Npcf_EventExposure_Notify includes a QoSrequirement of a performed service. The AF network element sends aresponse message to the PCF network element.

Optionally, after a period of time, when detecting that the first QoStarget can be met, the access network apparatus notifies the SMF networkelement, so that the SMF network element can reuse the first QoS targetto transmit a service.

FIG. 16 is a flowchart of a QoS flow control method according toEmbodiment 9 of this application. A difference from the foregoingembodiment lies in that in this embodiment, when a first target of a QoSflow cannot be met, a PCF network element determines to delete or modifya QoS policy rule that is of a service and that corresponds to the QoSflow. As shown in FIG. 16 , the method provided in this embodimentincludes the following steps.

Step S901: The PCF network element receives first indication informationsent by a session management function SMF network element, where thefirst indication information is used to indicate that a first QoS targetof a service cannot be met, and the first QoS target includes a firstGBR.

The first QoS target of the service is determined by the SMF networkelement based on a first QoS target that is of the QoS flow of theservice and that is sent by an access network apparatus. The accessnetwork apparatus sends the first indication information to the SMFnetwork element when the first target of the QoS flow of the servicecannot be met. The first indication information is used to indicate thatthe first QoS target of the QoS flow cannot be met, and the first QoStarget of the QoS flow includes a first GFBR.

After receiving the first indication information sent by the accessnetwork apparatus, the SMF network element determines the first GBR ofthe service based on the first GFBR of the QoS flow, adds the first GBRof the service to the first indication information, and sends the firstindication information to the PCF network element, to indicate that thefirst QoS target of the service cannot be met.

Step S902: The PCF network element does not process a QoS policy rule ofthe service if the PCF network element receives, in a first preset time,second indication information sent by the SMF network element, where thesecond indication information is used to indicate that the first QoStarget is met; or the PCF network element deletes or modifies a QoSpolicy rule of the service if the PCF network element does not receive,in a first preset time, second indication information sent by the SMFnetwork element.

In this embodiment, the first preset time may be implemented by using atimer, and a timing time of the timer is equal to the first preset time.The PCF network element starts the timer after receiving the firstindication information. Before the timer expires, if the PCF networkelement receives the second indication information sent by the SMFnetwork element, the PCF network element does not process the QoS policyrule of the service; or if the PCF network element does not receive thesecond indication information sent by the SMF network element, the PCFnetwork element deletes or modifies the QoS policy rule of the service.In this application, that the PCF network element does not process a QoSpolicy rule of the service means that the PCF network element does notdelete or modify the QoS policy rule of the service, but it is notensured that the PCF network element does not perform a possibleprocessing operation in another normal program.

After sending the first indication information, the access networkapparatus detects, in a second preset time, whether the first QoS targetof the QoS flow can be met. If the first QoS target of the QoS flow canbe met in the second preset time, the access network apparatus sends thesecond indication information to the SMF network element. If the firstQoS target of the QoS flow cannot be met when the second preset timeends, optionally, the access network apparatus may send third indicationinformation to the SMF network element, where the third indicationinformation is used to indicate that the first QoS target of the QoSflow cannot be met; or the access network apparatus does not send anymessage to the SMF network element. After receiving the third indicationinformation sent by the access network apparatus, the SMF networkelement determines the first QoS target of the service based on thefirst QoS target of the QoS flow, and sends the third indicationinformation to the PCF network element, to indicate that the first QoStarget of the service cannot be met.

Optionally, the PCF network element deletes or modifies the QoS policyrule of the service if the PCF network element receives, in the firstpreset time, third indication information sent by the SMF networkelement, where the third indication information is used to indicate thatthe first QoS target of the service cannot be met. In this embodiment,modifying the QoS policy rule of the service is modifying QoS-relatedcontent in the QoS policy rule of the service, for example, modifying aGBR and an MBR.

In this embodiment, if the PCF network element does not receive, in thefirst preset time, the second indication information sent by the accessnetwork apparatus, the PCF network element determines that the firsttarget of the service cannot be met, and the PCF network element deletesor modifies the QoS policy rule of the service. Modifying the QoS policyrule is modifying the first QoS target in the QoS policy rule of theservice to a second QoS target. An existing deletion procedure may beused for a QoS policy rule deletion procedure of the service, and anexisting modification procedure or a modification manner provided inEmbodiment 10 of this application may be used for a QoS policy rulemodification procedure of the service. For details, refer to thefollowing embodiments. The details are not described herein.

Optionally, after receiving the first indication information, the PCFnetwork element determines, based on the first indication information,an operation to be performed on the QoS policy rule of the service. Theoperation is the deleting or modifying a QoS policy rule of the service,and a state of the operation is a to-be-performed state. Afterdetermining the operation to be performed on the QoS policy rule of theservice, the PCF network element does not immediately perform theoperation, but marks the state of the operation as the to-be-performedstate. The PCF network element deletes state information of theoperation if the PCF network element receives, in the first preset time,the second indication information sent by the SMF network element; orthe PCF network element deletes or modifies the QoS policy rule of theservice if the PCF network element does not receive, in the first presettime, the second indication information sent by the SMF network element.

That the PCF network element determines to perform the modificationoperation on the QoS policy rule of the service includes: The PCFnetwork element determines a second QoS target in the QoS policy rule.Because determining the operation to be performed on the QoS policy ruleand detecting whether the second indication information is received maybe performed concurrently, the method in this application can shorten atime for modifying the QoS policy rule and reduce impact on the servicecompared with determining, after the first preset time, to perform themodification operation on the QoS policy rule.

In this embodiment, the PCF network element receives the firstindication information sent by the SMF network element, where the firstindication information is used to indicate that the first QoS target ofthe service cannot be met, and the first QoS target includes the firstGBR. The PCF network element does not process the QoS policy rule of theservice if the PCF network element receives, in the first preset time,the second indication information sent by the SMF network element, wherethe second indication information is used to indicate that the first QoStarget is met. The PCF network element deletes or modifies the QoSpolicy rule of the service if the PCF network element does not receive,in the first preset time, the second indication information sent by theSMF network element. The PCF network element deletes or modifies the QoSpolicy rule of the service to delete the QoS flow of the service. In themethod, when a QoS target of the QoS flow cannot be met, the PCF networkelement does not immediately delete or modify the QoS policy rule thatis of the service and that corresponds to the QoS flow. Instead, the PCFnetwork element deletes or modifies the QoS policy rule of the serviceonly when the QoS target of the QoS flow still cannot be met within adelay of the first preset time, to avoid a problem that a QoS flowservice cannot be served or quality of service of a service is reducedbecause the PCF network element immediately deletes or modifies the QoSflow when resources of the access network apparatus are temporarilyshort.

FIG. 17 is a flowchart of a QoS flow control method according toEmbodiment 10 of the present invention. It should be noted that themethods in Embodiment 9 and Embodiment 10 may be independently used, ormay be used in combination. When the method in Embodiment 9 isindependently used, after determining to modify the QoS policy rule, thePCF network element modifies the QoS policy rule in an existingmodification procedure. When Embodiment 9 and Embodiment 10 arecombined, after determining to modify the QoS policy rule, the PCFnetwork element modifies the QoS policy rule in the method in Embodiment10. As shown in FIG. 17 , the method provided in this embodimentincludes the following steps.

Step Snot A PCF network element receives first indication informationsent by a session management function SMF network element, where thefirst indication information is used to indicate that a first QoS targetof a service cannot be met, and the first QoS target includes a firstGBR.

Step S1102: The PCF network element determines a second QoS target ofthe service based on QoS policy information, where the second QoS targetincludes a second GBR, and the QoS policy information includes at leastfirst QoS control information and second QoS control information.

In this embodiment, because the at least two pieces of QoS controlinformation included in the QoS policy information can meet a QoSrequirement of the service, the second QoS target that is of the serviceand that is determined by the PCF network element based on the QoScontrol information can meet the QoS requirement of the service.Different from the prior art, in the solution in this embodiment, a QoStarget of the service is modified from the first QoS target to thesecond QoS target, and QoS quality of the service is not reduced.

In this embodiment, the PCF network element may determine the second QoStarget of the service in the following manners:

In a first manner, if the QoS policy information further includes atleast priority information of the first QoS control information andpriority information of the second QoS control information, the PCFnetwork element determines the second QoS target of the service based onthe priority information of the first QoS control information and thepriority information of the second QoS control information that areincluded in the QoS policy information.

For example, if the QoS policy information includes QoS controlinformation whose priority is the same as that of QoS controlinformation corresponding to the first QoS target, the PCF networkelement determines the second QoS target based on the QoS controlinformation whose priority is the same as that of the QoS controlinformation corresponding to the first QoS target. If the QoS policyinformation does not include QoS control information whose priority isthe same as that of QoS control information corresponding to the firstQoS target, the PCF network element selects QoS control information witha secondary priority in the QoS control information corresponding to thefirst QoS target, and determines the second QoS target based on the QoScontrol information with the secondary priority.

In a second manner, the PCF network element determines the second QoStarget of the service based on GBR information of the first QoS controlinformation and GBR information of the second QoS control informationthat are included in the QoS policy information.

When the QoS policy information includes GBR information of each pieceof QoS control information, the PCF network element determines thesecond QoS target of the service based on the GBR information of the QoScontrol information. For example, the PCF network element selects QoScontrol information with a maximum GBR from remaining QoS information,and determines the second QoS target based on the QoS controlinformation with the maximum GBR.

In a third manner, the PCF network element determines at least one thirdQoS target based on the at least two pieces of QoS control informationincluded in the QoS policy information; the PCF network element sendsthe third QoS target to the SMF network element; the PCF network elementreceives a fourth QoS target sent by the SMF network element, where thefourth QoS target is determined by the SMF network element based on aQoS target that can be currently met by an access network apparatus; andthe PCF network element determines the second QoS target based on thefourth QoS target.

The QoS target that can be currently met by the access network apparatusis a target of a QoS flow of the service, and the third QoS targetdetermined by the PCF network element is a QoS target of the service.After receiving the third QoS target of the service, the SMF networkelement determines a third QoS target of the QoS flow based on the thirdQoS target of the service, and sends the third QoS target of the QoSflow to the access network apparatus. The access network apparatusdetermines a fourth target of the QoS flow based on the third QoS targetof the QoS flow, and sends the fourth target of the QoS flow to the SMFnetwork element. The SMF network element determines the fourth QoStarget of the service based on the fourth target of the QoS flow, andsends the fourth QoS target of the service to the PCF network element.The PCF network element determines the second QoS target of the servicebased on the fourth QoS of the service.

When determining the second QoS target of the service based on thefourth QoS target of the service, the PCF network element may directlyuse the fourth QoS target of the service as the second QoS target of theservice, or may process the fourth QoS target of the service to obtainthe second QoS target of the service. For example, a GBR included in thefourth QoS target of the service fluctuates in a specific range and thenis used as the second QoS target of the service.

In the first two manners, the PCF network element determines the secondQoS target of the service in a manner of the PCF network element. In thethird manner, the PCF network element and the access network apparatusdetermine the second QoS target of the service through negotiation, sothat it can be ensured that the second QoS target determined for theservice matches a resource of the access network apparatus, and theresource of the access network apparatus can be used to a maximumextent.

In a fourth manner, the PCF network element receives a fifth QoS targetsent by the SMF network element, where the fifth QoS target isdetermined by the SMF network element based on a QoS target that can becurrently met by the access network apparatus; and the PCF networkelement determines the second QoS target based on the fifth QoS target.

The QoS target that can be met by the access network apparatus is a QoStarget that can be met by a QoS flow of the service. The SMF networkelement determines the fifth QoS target of the service based on the QoStarget that can be met by the QoS flow of the service, and sends thefifth QoS target of the service to the PCF network element. The PCFnetwork element determines the second QoS target of the service based onthe fifth QoS target of the service.

In this manner, the PCF network element and the access network apparatusdetermine the second QoS target of the service through negotiation. Adifference from the third manner in which the PCF network elementtriggers the access network apparatus to send the QoS target that can bemet by the access network apparatus lies in that in the fourth manner,when the first QoS target of the QoS flow cannot be met, the accessnetwork apparatus actively reports the QoS target that can be currentlymet by the access network apparatus, so that the SMF network elementdetermines the fifth QoS target of the service based on the QoS targetthat can be currently met by the access network apparatus, and sends thefifth QoS target of the service to the PCF network element. Therefore,it can be ensured that the second QoS target determined for the servicematches a resource of the access network apparatus, and the resource ofthe access network apparatus can be used to a maximum extent.

Step S1103: The PCF network element sends the second QoS target to theSMF network element.

The PCF network element sends the second QoS target of the service tothe SMF network element. The SMF network element determines a second QoStarget of the QoS flow based on the second QoS target of the service,and sends the second QoS target of the QoS flow to the access networkapparatus, so that the access network apparatus modifies the QoS flow.

In this embodiment, the PCF network element receives the firstindication information sent by the SMF network element, where the firstindication information is used to indicate that the first QoS target ofthe service cannot be met, and the first QoS target includes the firstGBR. The PCF network element determines the second QoS target of theservice based on the QoS policy information, where the second QoS targetincludes the second GBR, and the QoS policy information includes the atleast first QoS control information and second QoS control information.The PCF network element sends the second QoS target to the SMF networkelement. Because the at least two pieces of QoS control informationincluded in the QoS policy information can meet a QoS requirement of theservice, the second QoS target that is of the service and that isdetermined based on the QoS control information can also meet the QoSrequirement of the service. Different from the prior art, in thesolution in this embodiment, a QoS target of the service is modifiedfrom the first QoS target to the second QoS target, and QoS quality ofthe service is not reduced.

FIG. 18A and FIG. 18B are a signaling flowchart of a QoS flow controlmethod according to Embodiment 11 of this application. As shown in FIG.18A and FIG. 18B, the method provided in this embodiment includes thefollowing steps.

Step S1201: UE establishes a PDU session with a network.

For a session establishment process, refer to an existing establishmentprocedure. Details are not described herein.

Step S1202: When an AF network element determines to establish a servicefor the UE, the AF network element sends service information and atleast two GBR QoS requirements to a PCF network element.

The AF network element may add the service information and the at leasttwo GBR QoS requirements to an Npcf_PolicyAuthorization_create_serviceservice procedure, and send the service procedure to the PCF networkelement. The GBR QoS requirement includes a notification controlindication. Optionally, the service procedure further includes priorityinformation of two GBR QoS requirements.

Step S1203: The PCF network element sends at least two pieces of GBR QoScontrol information to an SMF network element.

The PCF network element may add the at least two pieces of GBR QoScontrol information to an Npcf_SMPolicyControl_UpdateNotify service, andsend the service to the SMF network element. The service is sent by thePCF network element based on a service request of the AF networkelement, and the GBR QoS control information is generated by the PCFnetwork element based on the GBR QoS requirement sent by the AF networkelement. Optionally, the service further includes priority informationof the GBR QoS control information.

Step S1204: The SMF network element establishes a corresponding QoS flowbased on a message sent by the PCF network element.

The SMF network element may establish the corresponding QoS flow basedon the service message sent by the PCF network element. In anestablishment process, the SMF network element activates thecorresponding QoS flow based on the priority information of the GBR QoScontrol information. To be specific, the SMF network element first usesGBR QoS control information with a highest priority to establish the QoSflow, where a QoS target corresponding to the GBR QoS controlinformation with the highest priority is a first QoS target. When theSMF network element does not obtain the priority information of the GBRQoS control information, the SMF network element determines, based on abandwidth requirement priority of the GBR QoS control information, topreferably use QoS control information with a higher bandwidthrequirement to establish the QoS flow, where a QoS target correspondingto the QoS control information with the higher bandwidth requirement isa first QoS target.

Step S1205: The UE establishes a QoS flow based on notification controlwith the network.

In this embodiment, in a process in which the UE establishes the QoSflow with the network, the SMF network element sends at least two QoStargets to an access network apparatus.

Step S1206: The access network apparatus detects that the first QoStarget of the QoS flow cannot be met, and a profile of the QoS flowincludes notification control.

Step S1207: The access network apparatus sends first indicationinformation to an AMF network element.

The access network apparatus may add the first indication information toan N2 message, and send the N2 message to the AMF network element. TheN2 message includes a PDU session ID and N2 SM information. The N2 SMinformation includes a QoS flow identifier (QFI) and the firstindication information, and the first indication information is used toindicate that the first QoS target of the QoS flow cannot be met.

Step S1208: The AMF network element sends the first indicationinformation to the SMF network element.

The AMF network element may add the first indication information to anNsmf_PDUSessionUpdateSMContext message, and send the message to the SMFnetwork element. The message includes a QFI and the first indicationinformation.

Step S1209: The SMF network element sends the first indicationinformation to the PCF network element.

After receiving the first indication information sent by the AMF networkelement, the SMF network element determines a first QoS target of theservice based on the first QoS target of the QoS flow, adds the firstQoS target of the service to the first indication information, and sendsthe first indication information to the PCF network element. The SMFnetwork element may add the first indication information to anNsmf_EventExposure-Notify message, and send the message to the PCFnetwork element.

Step S1210: The PCF network element starts a timer.

Step S1211: The access network apparatus detects, in a second presettime, that the first QoS target of the QoS flow is met.

Step S1212: The access network apparatus sends second indicationinformation to the AMF network element.

The second indication information is used to indicate that the first QoStarget of the QoS flow is met. The access network apparatus may add thesecond indication information to an N2 message, and send the N2 messageto the AMF network element. The message includes a PDU session ID and N2SM information. The N2 SM information includes a QFI and the secondindication information.

Step S1213: The AMF network element sends the second indicationinformation to the SMF network element.

The AMF network element may add the second indication information to anNsmf_PDUSessionUpdateSMContext message, and send the message to the SMFnetwork element. The message further includes a QFI. When receiving thesecond indication message, the SMF network element deletes the timer,and notifies the PCF network element of the event (that is, the firstQoS target is reached). The SMF network element deletes stateinformation of an operation of the QoS flow.

Step S1214: The SMF network element sends the second indicationinformation to the PCF network element.

The second indication information is used to indicate that the first QoStarget of the service is met. The SMF network element may add the secondindication information to an Nsmf_EventExposure-Notify message, and sendthe message to the PCF network element.

Step S1215: The PCF network element notifies the AF network element ofan event that the first QoS target of the service is met.

When notifying the AF network element of the event that the first QoStarget of the service is met, the PCF network element determines tomodify a QoS policy rule of the service. In this case, the PCF networkelement determines a second QoS target of the service. For a specificmanner of determining the second QoS target, refer to the description inEmbodiment 10. Details are not described herein again.

Step S1216: The PCF network element initiates a session managementpolicy modification procedure (including the second QoS target of theservice) to the SMF network element.

After receiving the second QoS target of the service, the SMF networkelement determines a second QoS target of the QoS flow based on thesecond QoS target of the service.

Step S1217: Perform a modification procedure for the QoS flow.

Optionally, the modification procedure for the QoS flow includes thefollowing steps (not shown in the figure).

S12170: The SMF network element sends a deletion or modification requestfor the QoS flow (including the second QoS target of the QoS flow) tothe AMF network element.

After receiving the second QoS that is of the service and that is sentby the PCF network element, the SMF network element determines thesecond QoS target of the QoS flow based on the second QoS target of theservice, and then the SMF network element sendsNamf_Communication_N1N2MessageTransfer to the AMF network element. Themessage includes N2 SM information and an N1 SM container. The N2 SMinformation includes a PDU session ID, a QFI, and a QoS profile(including the second QoS target). The N1 SM container includes a PDUsession ID, a QoS rule (including the first QoS target) that cannot bemet, and an operation (for example, deletion or modification) of the QoSrule.

S12171: The AMF network element sends the deletion or modificationrequest for the QoS flow (including the second QoS target of the QoSflow) to the access network apparatus.

The AMF network element may add the deletion or modification request forthe QoS flow to an N2 PDU session request, and send the N2 PDU sessionrequest to the access network apparatus. The request includes N2 SMinformation received from the SMF network element and a NAS message. TheNAS message includes a PDU session ID and an N1 SM container.

S12172: The access network apparatus performs a specific procedure withthe UE based on the second QoS target of the QoS flow.

For example, when the UE accesses a 3GPP RAN, an RRC connectionreconfiguration is performed between the UE and the access networkapparatus to modify a corresponding RAN resource.

S12173: The access network apparatus interacts with a core networkdevice to modify the QoS flow.

An existing procedure may be used for a process in which the accessnetwork apparatus interacts with the core network device. In thisembodiment, the interaction process is described by using an example inwhich communication is performed in a network architecture through aservice-based interface.

S12174: The access network apparatus sends an N2 session response to theAMF network element.

The N session response message includes N2 SM information.

S12175: The AMF network element uses an Namf_PDUSession_UpdateSMContextservice operation, where the service includes N2 SM information. The SMFnetwork element sends an Nsmf_PDUSession_UpdateSMContext response to theAMF network element.

S22176: The UE sends a NAS message to respond to a PDU sessionmodification command, where the NAS message includes a PDU session IDand an N1 SM container, and the N1 SM container is determined by the PDUsession modification command.

S12177: The access network apparatus forwards the NAS message to the AMFnetwork element.

S12178: The AMF network element forwards the N1 SM container to the SMFnetwork element by using Nsmf_PDUSession_UpdateSMContext. The SMFnetwork element sends the Nsmf_PDUSession_UpdateSMContext response tothe AMF network element.

S12179: The SMF network element performs a PDU session modificationprocedure with a UPF.

S12180: The SMF network element sends Nsmf_EventExposure_Notify to thePCF network element, where Nsmf_EventExposure_Notify includes anaffected PCC rule. The PCF network element sends a response message tothe SMF network element.

S12181: The PCF network element sends Nsmf_EventExposure_Notify to theAF network element, where Nsmf_EventExposure_Notify includes a QoSrequirement of a performed service. The AF network element sends aresponse message to the PCF network element.

Optionally, after a period of time, when detecting that the first QoStarget can be met, the access network apparatus notifies the SMF networkelement, so that the SMF network element can reuse the first QoS targetto transmit a service.

FIG. 19 is a flowchart of a QoS flow control method according toEmbodiment 12 of this application. A difference from the foregoingembodiment lies in that in this embodiment, when a first target of a QoSflow cannot be met, an AF network element determines to delete or modifya QoS requirement that is of a service and that corresponds to the QoSflow, to trigger modification of the QoS flow. As shown in FIG. 19 , themethod provided in this embodiment includes the following steps.

Step S1301: The AF network element receives first indication informationsent by a PCF network element, where the first indication information isused to indicate that a first QoS target of a service cannot be met, andthe first QoS target includes a first GBR.

The first QoS target of the service is determined by an SMF networkelement based on a first QoS target that is of the QoS flow of theservice and that is sent by an access network apparatus. The accessnetwork apparatus sends the first indication information to the SMFnetwork element when the first target of the QoS flow of the servicecannot be met. The first indication information is used to indicate thatthe first QoS target of the QoS flow cannot be met, and the first QoStarget of the QoS flow includes a first GFBR.

After receiving the first indication information sent by the accessnetwork apparatus, the SMF network element determines the first GBR ofthe service based on the first GFBR of the QoS flow, adds the first GBRof the service to the first indication information, and sends the firstindication information to the PCF network element, to indicate that thefirst QoS target of the service cannot be met. The PCF network elementsends the first indication information to the AF network element.

Step S1302: The AF network element does not process a QoS requirement ofthe service if the AF network element receives, in a first preset time,second indication information sent by the PCF network element, where thesecond indication information is used to indicate that the first QoStarget is met; or the AF network element deletes or modifies a QoSrequirement of the service if the AF network element does not receive,in a first preset time, second indication information sent by the PCFnetwork element.

In this embodiment, the first preset time may be implemented by using atimer, and a timing time of the timer is equal to the first preset time.The AF network element starts the timer after receiving the firstindication information. Before the timer expires, if the AF networkelement receives the second indication information sent by the PCFnetwork element, the AF network element does not process the QoSrequirement of the service; or if the AF network element does notreceive the second indication information sent by the PCF networkelement, the AF network element deletes or modifies the QoS requirementof the service. In this application, that the AF network element doesnot process a QoS requirement of the service means that the AF networkelement does not delete or modify the QoS requirement of the service,but it is not ensured that the AF network element does not perform apossible processing operation in another normal program.

After sending the first indication information, the access networkapparatus detects, in a second preset time, whether the first QoS targetof the QoS flow can be met. If the first QoS target of the QoS flow canbe met in the second preset time, the access network apparatus sends thesecond indication information to the SMF network element. If the firstQoS target of the QoS flow cannot be met when the second preset timeends, optionally, the access network apparatus may send third indicationinformation to the SMF network element, where the third indicationinformation is used to indicate that the first QoS target of the QoSflow cannot be met; or the access network apparatus does not send anymessage to the SMF network element. After receiving the third indicationinformation sent by the access network apparatus, the SMF networkelement determines the first QoS target of the service based on thefirst QoS target of the QoS flow, and sends the third indicationinformation to the PCF network element, to indicate that the first QoStarget of the service cannot be met. The PCF network element sends thefirst indication information to the AF network element.

Optionally, the AF network element deletes or modifies the QoSrequirement of the service if the AF network element receives, in thefirst preset time, third indication information sent by the PCF networkelement, where the third indication information is used to indicate thatthe first QoS target of the service cannot be met. In this embodiment,modifying the QoS requirement of the service is modifying QoS-relatedcontent in the QoS requirement of the service, for example, modifying aGBR and an MBR.

In this embodiment, if the AF network element does not receive, in thefirst preset time, the second indication information sent by the PCFnetwork element, the AF network element determines that the first targetof the service cannot be met, and the AF network element deletes ormodifies the QoS requirement of the service. Modifying the QoSrequirement is modifying the first QoS target in the QoS requirement ofthe service to a second QoS target. An existing deletion procedure maybe used for a QoS requirement deletion procedure of the service, and anexisting modification procedure or a modification manner provided inEmbodiment 13 of this application may be used for a QoS requirementmodification procedure of the service. For details, refer to thefollowing embodiments. The details are not described herein.

Optionally, after receiving the first indication information, the AFnetwork element determines, based on the first indication information,an operation to be performed on the QoS requirement of the service. Theoperation is the deleting or modifying a QoS requirement of the service,and a state of the operation is a to-be-performed state. Afterdetermining the operation to be performed on the QoS requirement of theservice, the AF network element does not immediately perform theoperation, but marks the state of the operation as the to-be-performedstate. The AF network element deletes state information of the operationif the AF network element receives, in the first preset time, the secondindication information sent by the PCF network element; or the AFnetwork element deletes or modifies the QoS requirement of the serviceif the AF network element does not receive, in the first preset time,the second indication information sent by the PCF network element.

That the AF network element determines to perform the modificationoperation on the QoS requirement of the service includes: The AF networkelement determines the second QoS target in the QoS requirement. Becausedetermining the modification operation to be performed on the QoSrequirement and detecting whether the second indication information isreceived may be performed concurrently, the method in this applicationcan shorten a time for modifying the QoS requirement and reduce impacton the service compared with determining, after the first preset time,to perform the modification operation on the QoS requirement.

In this embodiment, the AF network element receives the first indicationinformation sent by the PCF network element, where the first indicationinformation is used to indicate that the first QoS target of the servicecannot be met, and the first QoS target includes the first GBR. The AFnetwork element does not process the QoS requirement of the service ifthe AF network element receives, in the first preset time, the secondindication information sent by the PCF network element, where the secondindication information is used to indicate that the first QoS target ismet. The AF network element deletes or modifies the QoS requirement ofthe service if the AF network element does not receive, in the firstpreset time, the second indication information sent by the PCF networkelement. The AF network element deletes or modifies the QoS requirementof the service to trigger the SMF network element to modify or deletethe QoS flow of the service. In the method, when a QoS target of the QoSflow cannot be met, the AF network element does not immediately deleteor modify the QoS requirement that is of the service and thatcorresponds to the QoS flow. Instead, the AF network element deletes ormodifies the QoS requirement of the service only when the QoS target ofthe QoS flow still cannot be met within a delay of the first presettime, to avoid a problem that a QoS flow service cannot be served orquality of service of a service is reduced because the AF networkelement immediately deletes or modifies the QoS flow when resources ofthe access network apparatus are temporarily short.

FIG. 20 is a flowchart of a QoS flow control method according toEmbodiment 13 of the present invention. It should be noted that themethods in Embodiment 12 and Embodiment 13 may be independently used, ormay be used in combination. When the method in Embodiment 12 isindependently used, after determining to modify the QoS requirement, theAF network element modifies the QoS requirement in an existingmodification procedure. When Embodiment 12 and Embodiment 13 arecombined, after determining to modify the QoS requirement, the AFnetwork element modifies the QoS requirement in the method in Embodiment13. As shown in FIG. 20 , the method provided in this embodimentincludes the following steps.

Step S1401: An AF network element receives first indication informationsent by a PCF network element, where the first indication information isused to indicate that a first QoS target of a service cannot be met, andthe first QoS target includes a first GBR.

Step S1402: The AF network element determines a second QoS target of theservice based on QoS policy information, where the second QoS targetincludes a second GBR, and the QoS policy information includes at leastfirst QoS requirement information and second QoS requirementinformation.

In this embodiment, because the at least two pieces of QoS requirementinformation included in the QoS policy information can meet a QoSrequirement of the service, the second QoS target that is of the serviceand that is determined by the AF network element based on QoS controlinformation can meet the QoS requirement of the service. Different fromthe prior art, in the solution in this embodiment, a QoS target of theservice is modified from the first QoS target to the second QoS target,and QoS quality of the service is not reduced.

In this embodiment, the AF network element may determine the second QoStarget of the service in the following manners:

In a first manner, if the QoS policy information further includes atleast priority information of the first QoS requirement information andpriority information of the second QoS requirement information, the AFnetwork element determines the second QoS target of the service based onthe priority information of the first QoS requirement information andthe priority information of the second QoS requirement information thatare included in the QoS policy information.

For example, if the QoS policy information includes QoS requirementinformation whose priority is the same as that of QoS requirementinformation corresponding to the first QoS target, the AF networkelement determines the second QoS target based on the QoS requirementinformation whose priority is the same as that of the QoS requirementinformation corresponding to the first QoS target. If the QoS policyinformation does not include QoS requirement information whose priorityis the same as that of QoS requirement information corresponding to thefirst QoS target, the AF network element selects QoS requirementinformation with a secondary priority in the QoS requirement informationcorresponding to the first QoS target, and determines the second QoStarget based on the QoS requirement information with the secondarypriority.

In a second manner, the AF network element determines the second QoStarget of the service based on GBR information of first QoS controlinformation and GBR information of second QoS control information thatare included in the QoS policy information.

When the QoS policy information includes a GBR requirement of each pieceof QoS control information, the AF network element selects QoSrequirement information with a maximum GBR from remaining QoSrequirement information based on the GBR information of the QoSrequirement information, and determines the second QoS target based onthe QoS requirement information with the maximum GBR.

In a third manner, the AF network element determines at least one thirdQoS target based on the at least two pieces of QoS requirementinformation included in the QoS policy information; the AF networkelement sends the third QoS target to the PCF network element; the AFnetwork element receives a fourth QoS target sent by the PCF networkelement, where the fourth QoS target is determined by an SMF networkelement based on a QoS target that can be currently met by an accessnetwork apparatus; and the AF network element determines the second QoStarget based on the fourth QoS target.

The QoS target that can be currently met by the access network apparatusis a target of a QoS flow of the service, and the third QoS targetdetermined by the AF network element is a QoS target of the service.After receiving the third QoS target of the service, the SMF networkelement determines a third QoS target of the QoS flow based on the thirdQoS target of the service, and sends the third QoS target of the QoSflow to the access network apparatus. The access network apparatusdetermines a fourth target of the QoS flow based on the third QoS targetof the QoS flow, and sends the fourth target of the QoS flow to the SMFnetwork element. The SMF network element determines the fourth QoStarget of the service based on the fourth target of the QoS flow, andsends the fourth QoS target of the service to the PCF network element.The PCF network element sends a fourth QoS flow of the service to the AFnetwork element. The AF network element determines the second QoS targetof the service based on the fourth QoS of the service.

When determining the second QoS target of the service based on thefourth QoS target of the service, the AF network element may directlyuse the fourth QoS target of the service as the second QoS target of theservice, or may process the fourth QoS target of the service to obtainthe second QoS target of the service. For example, a GBR included in thefourth QoS target of the service fluctuates in a specific range and thenis used as the second QoS target of the service.

In the first two manners, the AF network element determines the secondQoS target of the service in a manner of the AF network element. In thethird manner, the AF network element and the access network apparatusdetermine the second QoS target of the service through negotiation, sothat it can be ensured that the second QoS target determined for theservice matches a resource of the access network apparatus, and theresource of the access network apparatus can be used to a maximumextent.

In a fourth manner, the AF network element receives a fifth QoS targetsent by the PCF network element, where the fifth QoS target isdetermined by the SMF network element based on a QoS target that can becurrently met by the access network apparatus; and the AF networkelement determines the second QoS target based on the fifth QoS target.

The QoS target that can be met by the access network apparatus is a QoStarget that can be met by a QoS flow of the service. The SMF networkelement determines the fifth QoS target of the service based on the QoStarget that can be met by the QoS flow, and sends the fifth QoS targetto the AF network element.

In this manner, the AF network element and the access network apparatusdetermine the second QoS target of the service through negotiation. Adifference from the third manner in which the AF network elementtriggers the access network apparatus to send the QoS target that can bemet by the access network apparatus lies in that in the fourth manner,when the first QoS target of the QoS flow cannot be met, the accessnetwork apparatus actively reports the QoS target that can be currentlymet by the access network apparatus, so that the SMF network elementdetermines the fifth QoS target of the service based on the QoS targetthat can be currently met by the access network apparatus, and sends thefifth QoS target of the service to the PCF network element. Therefore,it can be ensured that the second QoS target determined for the servicematches a resource of the access network apparatus, and the resource ofthe access network apparatus can be used to a maximum extent.

Step S1403: The AF network element sends the second QoS target to thePCF network element.

The AF network element sends the second QoS target of the service to thePCF network element. The PCF network element sends the second QoS targetof the service to the SMF network element. The SMF network elementdetermines a second QoS target of the QoS flow based on the second QoStarget of the service, and sends the second QoS target of the QoS flowto the access network apparatus, so that the access network apparatusmodifies the QoS flow.

In this embodiment, the AF network element receives the first indicationinformation sent by the PCF network element, where the first indicationinformation is used to indicate that the first QoS target of the servicecannot be met, and the first QoS target includes the first GBR. The AFnetwork element determines the second QoS target of the service based onthe QoS policy information, where the second QoS target includes thesecond GBR, and the QoS policy information includes the at least firstQoS requirement information and second QoS requirement information. TheAF network element sends the second QoS target to the PCF networkelement. Because the at least two pieces of QoS requirement informationincluded in the QoS policy information can meet a QoS requirement of theservice, the second QoS target that is of the service and that isdetermined based on the QoS requirement information can also meet theQoS requirement of the service. Different from the prior art, in thesolution in this embodiment, a QoS target of the service is modifiedfrom the first QoS target to the second QoS target, and QoS quality ofthe service is not reduced.

FIG. 21A and FIG. 21B are a signaling flowchart of a QoS flow controlmethod according to Embodiment 14 of this application. As shown in FIG.18A and FIG. 18B, the method provided in this embodiment includes thefollowing steps.

Step S1501: UE establishes a PDU session (session) with a network.

For a session establishment process, refer to an existing establishmentprocedure. Details are not described herein.

Step S1502: When an AF network element determines to establish a servicefor the UE, the AF network element sends service information and atleast two GBR QoS requirements to a PCF network element.

The AF network element may add the service information and the at leasttwo GBR QoS requirements to an Npcf_PolicyAuthorization_create_serviceservice procedure, and send the service procedure to the PCF networkelement. The GBR QoS requirement includes a notification controlindication. Optionally, the service procedure further includes priorityinformation of two GBR QoS requirements.

Step S1503: The PCF network element sends at least two pieces of GBR QoScontrol information to an SMF network element.

The PCF network element may add the at least two pieces of GBR QoScontrol information to an Npcf_SMPolicyControl_UpdateNotify service, andsend the service to the SMF network element. The service is sent by thePCF network element based on a service request of the AF networkelement, and the GBR QoS control information is generated by the PCFnetwork element based on the GBR QoS requirement sent by the AF networkelement. Optionally, the service further includes priority informationof the GBR QoS control information.

Step S1504: The SMF network element establishes a corresponding QoS flowbased on a message sent by the PCF network element.

The SMF network element may establish the corresponding QoS flow basedon the service message sent by the PCF network element. In anestablishment process, the SMF network element activates thecorresponding QoS flow based on the priority information of the GBR QoScontrol information. To be specific, the SMF network element first usesGBR QoS control information with a highest priority to establish the QoSflow, where a QoS target corresponding to the GBR QoS controlinformation with the highest priority is a first QoS target. When theSMF network element does not obtain the priority information of the GBRQoS control information, the SMF network element determines, based on abandwidth requirement priority of the GBR QoS control information, topreferably use QoS control information with a higher bandwidthrequirement to establish the QoS flow, where a QoS target correspondingto the QoS control information with the higher bandwidth requirement isa first QoS target.

Step S1505: The UE establishes a QoS flow based on notification controlwith the network.

In this embodiment, in a process in which the UE establishes the QoSflow with the network, the SMF network element sends at least two QoStargets to an access network apparatus.

Step S1506: The access network apparatus detects that the first QoStarget of the QoS flow cannot be met, and a profile of the QoS flowincludes notification control.

Step S1507: The access network apparatus sends first indicationinformation to an AMF network element.

The access network apparatus may add the first indication information toan N2 message, and send the N2 message to the AMF network element. TheN2 message includes a PDU session ID and N2 SM information. The N2 SMinformation includes a QoS flow identifier (QFI) and the firstindication information, and the first indication information is used toindicate that the first QoS target of the QoS flow cannot be met.

Step S1508: The AMF network element sends the first indicationinformation to the SMF network element.

The AMF network element may add the first indication information to anNsmf_PDUSessionUpdateSMContext message, and send the message to the SMFnetwork element. The message includes a QFI and the first indicationinformation.

Step S1509: The SMF network element sends the first indicationinformation to the PCF network element.

The first indication information is used to indicate that a first QoStarget of the service cannot be met. After receiving the firstindication information sent by the AMF network element, the SMF networkelement determines the first QoS target of the service based on thefirst QoS target of the QoS flow, adds the first QoS target of theservice to the first indication information, and sends the firstindication information to the PCF network element. The SMF networkelement may add the first indication information to anNsmf_EventExposure-Notify message, and send the message to the PCFnetwork element.

Step S1510: The PCF network element sends the first indicationinformation to the AF network element.

The first indication information is used to indicate that the first QoStarget of the service cannot be met. The PCF network element may add thesecond indication information to an Nsmf_EventExposure-Notify message,and send the message to the AF network element.

Step S1511: The AF network element starts a timer.

Step S1512: The access network apparatus detects, in a second presettime, that the first QoS target of the QoS flow is met.

Step S1513: The access network apparatus sends second indicationinformation to the AMF network element.

The second indication information is used to indicate that the first QoStarget of the QoS flow is met. The access network apparatus may add thesecond indication information to an N2 message, and send the N2 messageto the AMF network element. The message includes a PDU session ID and N2SM information. The N2 SM information includes a QFI and the secondindication information.

Step S1514: The AMF network element sends the second indicationinformation to the SMF network element.

The AMF network element may add the second indication information to anNsmf_PDUSessionUpdateSMContext message, and send the message to the SMFnetwork element. The message further includes a QFI. When receiving thesecond indication message, the SMF network element deletes the timer,and notifies the PCF network element of the event (that is, the firstQoS target is reached). The SMF network element deletes stateinformation of an operation of the QoS flow.

Step S1515: The SMF network element sends the second indicationinformation to the PCF network element.

The second indication information is used to indicate that the first QoStarget of the service is met. The SMF network element may add the secondindication information to an Nsmf_EventExposure-Notify message, and sendthe message to the PCF network element.

Step S1516: The PCF network element sends the second indicationinformation to the AF network element.

The PCF network element may add the second indication information to anNsmf_EventExposure-Notify message, and send the message to the AFnetwork element. The AF network element determines, based on the secondindication information, to modify or delete a QoS requirement of theservice. When the AF network element determines to modify the QoSrequirement of the service, the AF network element determines a secondQoS target of the service based on the at least two QoS requirements.For a specific determining manner, refer to the description inEmbodiment 14. Details are not described herein again.

Step S1517: The AF network element initiates a service requirementdeletion or modification procedure (including the second QoS target ofthe service) to the PCF network element.

The AF network element may add the second QoS target of the service toan Npcf-PolicyQuthorization-create-service message, and send the messageto the PCF network element.

Step S1518: The PCF network element initiates a session managementpolicy modification procedure (including the second QoS target of theservice) to the SMF network element.

The PCF network element may add the second QoS target of the service toan Nsmf_EventExposure-Notify message, and send the message to the SMFnetwork element. The SMF network element determines a second QoS targetof the QoS flow based on the second QoS target of the service.

Step S1519: Perform a modification procedure for the QoS flow.

Optionally, the modification procedure for the QoS flow includes thefollowing steps (not shown in the figure).

S15190: The SMF network element sends a deletion or modification requestfor the QoS flow (including the second QoS target of the QoS flow) tothe AMF network element.

For example, after receiving the second QoS that is of the service andthat is sent by the PCF network element, the SMF network elementdetermines the second QoS target of the QoS flow based on the second QoStarget of the service, and then the SMF network element sendsNamf_Communication_N1N2MessageTransfer to the AMF network element. Themessage includes N2 SM information and an N1 SM container. The N2 SMinformation includes a PDU session ID, a QFI, and a QoS profile(including the second QoS target). The N1 SM container includes a PDUsession ID, a QoS rule (including the first QoS target) that cannot bemet, and an operation (for example, deletion or modification) of the QoSrule.

S15191: The AMF network element sends the deletion or modificationrequest for the QoS flow (including the second QoS target of the QoSflow) to the access network apparatus.

The AMF network element may add the deletion or modification request forthe QoS flow to an N2 PDU session request, and send the N2 PDU sessionrequest to the access network apparatus. The request includes N2 SMinformation received from the SMF network element and a NAS message. TheNAS message includes a PDU session ID and an N1 SM container.

S15192: The access network apparatus performs a specific procedure withthe UE based on the second QoS target of the QoS flow.

For example, when the UE accesses a 3GPP RAN, an RRC connectionreconfiguration is performed between the UE and the access networkapparatus to modify a corresponding RAN resource.

S15193: The access network apparatus interacts with a core networkdevice to modify the QoS flow.

An existing procedure may be used for a process in which the accessnetwork apparatus interacts with the core network device. In thisembodiment, the interaction process is described by using an example inwhich communication is performed in a network architecture through aservice-based interface.

S15194: The access network apparatus sends an N2 session response to theAMF network element.

The N session response message includes N2 SM information.

S15195: The AMF network element uses an Nsmf_PDUSession_UpdateSMContextservice operation, where the service includes N2 SM information. The SMFnetwork element sends an Nsmf_PDUSession_UpdateSMContext response to theAMF network element.

S15196: The UE sends a NAS message to respond to a PDU sessionmodification command, where the NAS message includes a PDU session IDand an N1 SM container, and the N1 SM container is determined by the PDUsession modification command.

S15197: The access network apparatus forwards the NAS message to the AMFnetwork element.

S15198: The AMF network element forwards the N1 SM container to the SMFnetwork element by using Nsmf_PDUSession_UpdateSMContext. The SMFnetwork element sends the Nsmf_PDUSession_UpdateSMContext response tothe AMF network element.

S15199: The SMF network element performs a PDU session modificationprocedure with a UPF.

S15200: The SMF network element sends Nsmf_EventExposure_Notify to thePCF network element, where Nsmf_EventExposure_Notify includes anaffected PCC rule. The PCF network element sends a response message tothe SMF network element.

S15201: The PCF network element sends Npcf_EventExposure_Notify to theAF network element, where Npcf_EventExposure_Notify includes a QoSrequirement of a performed service. The AF network element sends aresponse message to the PCF network element.

Optionally, after a period of time, when detecting that the first QoStarget can be met, the access network apparatus notifies the SMF networkelement, so that the SMF network element can reuse the first QoS targetto transmit a service.

It should be noted that when the method in this application is appliedto a roaming scenario, the PCF network element may be a visited PCF(v-PCF) network element or a home PCF (h-PCF) network element, and theSMF network element may be a visited SMF (v-SMF) network element or ahome SMF(h-SMF) network element. In addition, in the embodiments of thisapplication, a message exchanged between network elements is describedby using an architecture based on a service-based interface. Theforegoing embodiments are merely examples for description. A name of themessage exchanged in this application may be implemented by usinganother message name. For an interface architecture, a correspondingfunction is implemented by using a message name related to acorresponding interface architecture.

Embodiment 15 of this application provides an SMF network element. TheSMF network element includes modules configured to implement the methodperformed by the SMF network element in Embodiment 1 to Embodiment 14.

Embodiment 16 of this application provides an access network apparatus.The access network apparatus includes modules configured to implementthe method performed by the access network apparatus in Embodiment 1 toEmbodiment 14.

Embodiment 17 of this application provides a PCF network element. ThePCF network element includes modules configured to implement the methodperformed by the PCF network element in Embodiment 1 to Embodiment 14.

Embodiment 18 of this application provides an AF network element. The AFnetwork element includes modules configured to implement the methodperformed by the AF network element in Embodiment 1 to Embodiment 14.

FIG. 22 is a schematic structural diagram of an SMF network elementaccording to Embodiment 19 of this application. As shown in FIG. 22 ,the SMF network element includes a processor 11, a memory 12, and atransceiver 13. The memory 12 is configured to store an instruction, thetransceiver 13 is configured to communicate with another device, and theprocessor 11 is configured to execute the instruction stored in thememory 12, so that the SMF network element performs the method stepsperformed by the SMF network element in Embodiment 1 to Embodiment 14. Aspecific implementation and a technical effect are similar to those ofthe SMF network element in Embodiment 1 to Embodiment 14. Details arenot described herein again.

FIG. 23 is a schematic structural diagram of an access network apparatusaccording to Embodiment 20 of this application. As shown in FIG. 23 ,the access network apparatus includes a processor 21, a memory 22, and atransceiver 23. The memory 22 is configured to store an instruction, thetransceiver 23 is configured to communicate with another device, and theprocessor 21 is configured to execute the instruction stored in thememory 22, so that the access network apparatus performs the methodsteps performed by the access network apparatus in Embodiment 1 toEmbodiment 14. A specific implementation and a technical effect aresimilar to those of the access network apparatus in Embodiment 1 toEmbodiment 14. Details are not described herein again.

FIG. 24 is a schematic structural diagram of a PCF network elementaccording to Embodiment 21 of this application. As shown in FIG. 24 ,the PCF network element includes a processor 31, a memory 32, and atransceiver 33. The memory 32 is configured to store an instruction, thetransceiver 32 is configured to communicate with another device, and theprocessor 31 is configured to execute the instruction stored in thememory 32, so that the PCF network element performs the method stepsperformed by the PCF network element in Embodiment 1 to Embodiment 14. Aspecific implementation and a technical effect are similar to those ofthe PCF network element in Embodiment 1 to Embodiment 14. Details arenot described herein again.

FIG. 25 is a schematic structural diagram of an AF network elementaccording to Embodiment 22 of this application. As shown in FIG. 25 ,the AF network element includes a processor 41, a memory 42, and atransceiver 43. The memory 42 is configured to store an instruction, thetransceiver 42 is configured to communicate with another device, and theprocessor 41 is configured to execute the instruction stored in thememory 42, so that the AF network element performs the method stepsperformed by the AF network element in Embodiment 1 to Embodiment 14. Aspecific implementation and a technical effect are similar to those ofthe AF network element in Embodiment 1 to Embodiment 14. Details are notdescribed herein again.

Embodiment 23 of this application provides a computer readable storagemedium, applied to an SMF network element. The computer readable storagemedium stores an instruction. When the instruction is executed by acomputing apparatus, the SMF network element is enabled to perform themethod steps performed by the SMF network element in Embodiment 1 toEmbodiment 14. A specific implementation and a technical effect aresimilar to those of the SMF network element in Embodiment 1 toEmbodiment 14. Details are not described herein again.

Embodiment 24 of this application provides a computer readable storagemedium, applied to an access network apparatus. The computer readablestorage medium stores an instruction. When the instruction is executedby a computing apparatus, the access network apparatus is enabled toperform the method steps performed by the access network apparatus inEmbodiment 1 to Embodiment 14. A specific implementation and a technicaleffect are similar to those of the access network apparatus inEmbodiment 1 to Embodiment 14. Details are not described herein again.

Embodiment 25 of this application provides a computer readable storagemedium, applied to a PCF network element. The computer readable storagemedium stores an instruction. When the instruction is executed by acomputing apparatus, the PCF network element is enabled to perform themethod steps performed by the PCF network element in Embodiment 1 toEmbodiment 14. A specific implementation and a technical effect aresimilar to those of the PCF network element in Embodiment 1 toEmbodiment 14. Details are not described herein again.

Embodiment 26 of this application provides a computer readable storagemedium, applied to an AF network element. The computer readable storagemedium stores an instruction. When the instruction is executed by acomputing apparatus, the AF network element is enabled to perform themethod steps performed by the AF network element in Embodiment 1 toEmbodiment 14. A specific implementation and a technical effect aresimilar to those of the AF network element in Embodiment 1 to Embodiment14. Details are not described herein again.

The processor in the embodiments may be a general purpose processor, adigital signal processor (DSP), an application-specific integratedcircuit (ASIC), a field programmable gate array (FPGA) or anotherprogrammable logic device, a discrete gate or transistor logic device,or a discrete hardware component. The processor may implement or performthe methods, the steps, and logical block diagrams that are disclosed inthe embodiments of the present invention. The general purpose processormay be a microprocessor, or the processor may be any conventionalprocessor or the like. Steps in the methods disclosed with reference tothe embodiments of the present invention may be directly executed andcompleted by using a hardware decoding processor, or may be executed andcompleted by using a combination of hardware and software modules in thedecoding processor. A software module may be located in a mature storagemedium in the art, such as a random access memory (RAM), a flash memory,a read-only memory (ROM), a programmable read-only memory, anelectrically erasable programmable memory, or a register. The storagemedium is located in the memory 1002, and the processor 1001 reads aninstruction from the memory 1002 and completes the steps in theforegoing methods in combination with hardware of the processor.

The bus in this application may be an industry standard architecture(ISA) bus, a peripheral component interconnect (PCI) bus, an extendedindustry standard architecture (EISA) bus, or the like. The bus may beclassified into an address bus, a data bus, a control bus, and the like.For ease of representation, the bus in the accompanying drawings of thisapplication is not limited to only one bus or only one type of bus.

In the several embodiments provided in this application, it should beunderstood that the disclosed apparatus and method may be implemented inanother manner. For example, the foregoing described apparatusembodiment is merely an example. For example, division into the units ismerely logical function division and may be other division in an actualimplementation. For example, a plurality of units or components may becombined or integrated into another system, or some features may beignored or not performed. In addition, the displayed or discussed mutualcouplings or direct couplings or communication connections may beimplemented by using some interfaces. The indirect couplings orcommunication connections between the apparatuses or units may beimplemented in electronic, mechanical, or another form.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,and may be located in one position, or may be distributed on a pluralityof network units. Some or all of the units may be selected based on anactual requirement to achieve the objectives of the solutions of theembodiments.

In addition, function units in the embodiments of this application maybe integrated into one processing unit, or each of the units may existalone physically, or two or more units may be integrated into one unit.The integrated unit may be implemented in a form of hardware, or may beimplemented in a form of hardware and a software function unit.

What is claimed is:
 1. A method, comprising: receiving, by an accessnetwork apparatus, at least two quality of service (QoS) targets of aQoS flow from a session management function network element; in responseto determining a first QoS target of the QoS flow is not able to be metby the access network apparatus, determining, by the access networkapparatus based on an available resource and in the at least two QoStargets received from the session management function network element, asecond QoS target that is of the QoS flow and that is able to be met bythe access network apparatus, wherein the first QoS target comprises afirst guaranteed flow bit rate (GFBR), and the second QoS targetcomprises a second GFBR; and reporting, by the access network apparatusto the session management function network element, that the first QoStarget is not able to be met by the access network apparatus, and thesecond QoS target that is able to be met by the access networkapparatus.
 2. The method according to claim 1, wherein the QoS flow is aguaranteed bit rate QoS flow.
 3. A method, comprising: sending, by asession management function network element, at least two quality ofservice (QoS) targets of a QoS flow to an access network apparatus; andreceiving, by the session management function network element from theaccess network apparatus, indication information indicating that a firstQoS target of the QoS flow is not able to be met by the access networkapparatus, and a report of a second QoS target that is of the QoS flowand that is able to be met by the access network apparatus, wherein theat least two QoS targets comprise the second QoS target, the second QoStarget is determined based on an available resource, and wherein thefirst QoS target comprises a first guaranteed flow bit rate (GFBR), andthe second QoS target comprises a second GFBR.
 4. The method accordingto claim 3, further comprising: reporting, by the session managementfunction network element to a policy control function network element,that the first QoS target is not able to be met by the access networkapparatus, and the second QoS target that is able to be met by theaccess network apparatus.
 5. The method according to claim 3, furthercomprising: receiving, by the session management function networkelement, QoS policy information from a policy control function networkelement; and wherein sending, by the session management function networkelement, the at least two QoS targets to the access network apparatuscomprises: sending, by the session management function network elementbased on the QoS policy information, the at least two QoS targets to theaccess network apparatus.
 6. The method according to claim 5, whereinthe QoS policy information comprises at least two pieces of QoS controlinformation.
 7. The method according to claim 6, wherein each piece ofthe at least two pieces of QoS control information comprises one or moreof: a 5QI, an allocation and retention priority (ARP), a guaranteed bitrate (GBR), a maximum bit rate (MBR), or notification control.
 8. Themethod according to claim 3, wherein the QoS flow is a guaranteed bitrate QoS flow.
 9. An access network apparatus, comprising: a processor;and a non-transitory memory, wherein the processor is configured toexecute at least one instruction stored in the non-transitory memory to:receive at least two quality of service (QoS) targets of a QoS flow froma session management function network element; in response todetermining a first QoS target of the QoS flow is not able to be met bythe access network apparatus, determine, based on an available resourceand in the at least two QoS targets received from the session managementfunction network element, a second QoS target that is of the QoS flowand that is able to be met by the access network apparatus, wherein thefirst QoS target comprises a first guaranteed flow bit rate (GFBR), andthe second QoS target comprises a second GFBR; and report, to thesession management function network element, that the first QoS targetis not able to be met by the access network apparatus, and the secondQoS target that is able to be met by the access network apparatus. 10.The access network apparatus according to claim 9, wherein the QoS flowis a guaranteed bit rate QoS flow.
 11. A session management functionnetwork element, comprising: a processor; and a non-transitory memory,wherein the processor is configured to execute at least one instructionstored in the non-transitory memory to: send at least two quality ofservice (QoS) targets of a QoS flow to an access network apparatus; andreceive, from the access network apparatus, indication informationindicating that a first QoS target of the QoS flow is not able to be metby the access network apparatus, and a report of a second QoS targetthat is of the QoS flow and that is able to be met by the access networkapparatus, wherein the at least two QoS targets comprise the second QoStarget, the second QoS target is determined based on an availableresource, and wherein the first QoS target comprises a first guaranteedflow bit rate 9GFBR), and the second QoS target comprises a second GFBR.12. The session management function network element according to claim11, wherein the processor is further configured to execute the at leastone instruction to: receive QoS policy information from a policy controlfunction network element; and wherein sending the at least two QoStargets to the access network apparatus comprises: sending, based on theQoS policy information, the at least two QoS targets to the accessnetwork apparatus.
 13. The session management function network elementaccording to claim 12, wherein the QoS policy information comprises atleast two pieces of QoS control information.
 14. The session managementfunction network element according to claim 13, wherein each piece ofthe at least two pieces of QoS control information comprises one or moreof: a 5QI, an allocation and retention priority (ARP), a guaranteed bitrate (GBR), a maximum bit rate (MBR), or notification control.
 15. Thesession management function network element according to claim 12,wherein the processor is further configured to execute the at least oneinstruction to: report, to a policy control function network element,that the first QoS target is not able to be met by the access networkapparatus, and the second QoS target that is able to be met by theaccess network apparatus.
 16. The session management function networkelement according to claim 11, wherein the QoS flow is a guaranteed bitrate QoS flow.